Frequently Asked Questions

Q: Which access control paradigms are available?

A: Promethion Core supports all common access control paradigms. This includes simple time restricted access, daily quantity limits and combinations of both. For group control studies we offer paired feeding (including per cage adjustments for calorie restriction protocols) as well as yoked feeding (synchronized feeding). For pair feeding, it is possible to assign groups of cages as independent exemplars for a group of dependent cages. These will then be allocated the adjusted average consumption of all their exemplars.

Q: How complicated is access control to set up?

A: Promethion Live offers a simple no-code user interface that allows to click together access control programs. Simply choose the type of access control to implement and any necessary configuration (paired feeding, yoked feeding, time and duration limited feeding, or quantity limited feeding). The program will convert the inputs into a small script for execution automatically. For advanced use cases, or small adjustments to the parameters in an existing protocol, it is possible to directly edit the script as well.  

Q: What happens if the mouse is in the way of the access control door as it closes?

A: During calibration the access control unit stores the individual range of motion. If the door encounters too much resistance before reaching the end position, it will back out, pause a few seconds and retry the closure. All parameters (resistance threshold, retry interval) can be fine-tuned.

Q: How can I tell what the status of the food access control was during a recording?

A: The position of the food access door is recorded every second and saved as part of Promethion Core’s deep data field.

Q: Do you have food access control models for both rats and mice?

A: Yes, we have two models, one for mice and one for rats.

Q: Is the access control part of the food intake measurement system, or can it be used separately if I do not have a requirement for measuring food intake, but only for controlling it?

A: The AC-2 access control system is independent of the food intake measurement system. If installed, the AC-2 will use the food intake measurements to refine its calibration, but this is optional.

Q: How does Promethion Core measure body mass?

A: An enrichment habitat is suspended from a mass monitor, and the mass of the habitat is recorded every second and added to Promethion Core’s deep data field. Every time an animal climbs into the habitat, the mass readings become unstable and then stabilize again when the animal settles down in the habitat. Conversely, when an animal leaves the habitat, there is a brief period of unstable mass measurement followed by the mass of the empty habitat. Thus, the animal essentially tares the habitat and weighs itself with each entrance and exit. During analysis, a sophisticated algorithm extracts each accurate body mass measurement and interpolates between them to yield a “continuous” body mass recording.

Q: What if the animal doesn’t enter the habitat?

A: Most animals use the enrichment habitat frequently. In our experience, at least 95% of animals will use it often enough to yield excellent data. The side benefit is not causing handling stress by manual weighing.

Q: Can you get any additional information from the mass measurement sensors in this application?

A: Yes. For example, it is easy to detect grooming and scratching episodes that take place in the mass measurement habitat. Also, it is sometimes possible to detect whether an animal has eaten cached food. If an animal leaves the habitat and then re-enters it without having accessed the food or water hoppers, but if its body mass has nevertheless increased, it is likely to have eaten from a cached food store.

Q: Promethion Core has a very fast cycle time relative to the competition. Why is this?

A: The cycle time is the duration it takes to sample cage 1 through cage X and back to 1 in a multiplex system setup. The cycle time is governed by the time constant which is cage volume divided by the air flow rate. The time constant indicates the highest useful frequency to acquire gas measurements and, thus, determines the optimal cycle time.  Our time constant is ~4 minutes.  Having a cycle time faster than ~2 minutes adds no additional information to the metabolic data as the shape of the resultant graph will be the same.   This is the temporal resolution limit. 

The cycle time is calculated by summing the per cage analysis dwell times. For Promethion Core cages, this may be as short as 15 seconds/cage which results in a cycle time of 2.5 minutes and the highest temporal resolution in the industry, enabling users to quantify rapid changes in metabolism. Competitor multiplex systems have low cage airflow rates resulting in a time constant of 15 minutes and typical cycle times of 15-30 minutes, so they have low temporal resolution.  This blurs and flattens the resultant data. Competitor continuous systems (each cage has its own set of gas analyzers) also have similarly low effective temporal resolution due to their low cage air exchange rate and resultant low time constant. 

All this is achieved primarily through our high-resolution gas analyzers that detect the small changes per unit time inherent when pulling air through the cage at high flow rates, reducing the time constant and increasing temporal resolution.   

Q: In Promethion Core multiplexed metabolic measurement systems, each cage is sampled every 2.5 minutes. However, Promethion Live is also obtaining data from all system sensors (food intake, water intake, body mass, position, beam-breaks and so on) every second. How is the metabolic data synchronized with the data acquired from the other sensors?

A: The unique analytical environment interpolates between the metabolic measurements made on each cage, yielding a full set of data re-sampled to the same effective acquisition rate as the other sensors. This ensures that the metabolic and sensor data are perfectly synchronized. You will never have to face the headache of reconciling different sets of data acquired in different ways with different sampling and binning intervals again! Furthermore, the Promethion Core data stream may be synchronized with data streams from 3rd party devices such as telemetry, video, and optogenetic systems. 

Q: What corrections does Promethion Core make to the raw data for water vapor dilution and barometric pressure changes? And what equations do you use for calculating metabolic parameters from your raw data?

A: “Water vapor pressure and barometric pressure are measured directly, and the necessary corrections are made according to Dalton’s law of partial pressures.

The equations are described in the world’s only textbook of metabolic measurement, “Measuring Metabolic Rates: A Manual for Scientists”, by John R. B. Lighton, published by Oxford University press in 2008. Unlike all other metabolic phenotyping systems, Promethion Core’s data analysis is totally transparent. The data analysis scripts can be readily examined to show all the steps in the transition from raw data to final, publication-quality extracted data.

Q: Have your equations, and especially your technique for mathematical compensation for water vapor dilution, been rigorously validated?

A: The equations are described in the world’s only textbook of metabolic measurement, “Measuring Metabolic Rates: A Manual for Scientists”, by John R. B. Lighton, published by Oxford University press in 2008. Dr. Lighton is our President and chief scientist. With over 100 scientific publications using metabolic measurement, he is recognized as one of the world’s leading and most innovative experts in metabolic measurement. Dr. Lighton is also responsible for many of Sable’s equipment designs.  Validation of the calculations employed by Promethion were made using the “gold standard” of quantitative propane combustion and demonstrate practically perfect performance (Melanson EL, et. al., Am J Physiol Regul Integr Comp Physiol 2010)

Q: Can Promethion Core measure metabolic flux/bioenergetics?

A:  Yes, Promethion Core when integrated with our stable isotope analyzer enables the study of metabolic fluxes. This works by introducing 13C labeled food/tracer to the mouse or rat. The food/tracer can either be fully labeled (all carbon atoms labeled) or individual carbon atoms of interest may be labeled. The animal catabolizes the tracer and expels it in the form of 13CO2 which the analyzer detects. The dynamic range of our stable isotope analyzer can quantify the catabolism of both fully and singly labeled tracers. 

Q: I have heard of power failures causing the pumps of a metabolic phenotyping system to shut down, asphyxiating a whole group of expensive transgenic animals. Can this happen with the Promethion Core system?

A: No. Promethion Core uses pull-mode respirometry. The benefit is that the standard cages are never sealed, as with push mode systems, and air can freely enter and exit the cages in the event of a power failure. Your animals, your science and your budget are safe with Promethion Core.

Q: Our IACUC states that cages should be ventilated with at least 15 air exchanges per hour. Most metabolic phenotyping systems struggle to meet even a third of that figure. Can Promethion Core meet the specification, or do we have to spend time and effort requesting an exemption?

A: Promethion Core uses high flow rates of 2 LPM through each cage. For our mouse cages, this corresponds to about 12-15 air exchanges per hour, depending on how much cage volume is taken up by food hoppers, bedding, enrichment etc. Being able to use these high flow rates in a metabolic system is one of the main benefits of using gas analyzers that are specifically designed for flow-through respirometry. The CGF does not suffer from the degradation in signal to noise ratio that plagues other systems at higher flow rates. Promethion Core meets IACUC regulations without requiring exemptions.

Q: Are there any additional benefits to the higher flow rate?

A: The high flow rate translates to a lower concentration of CO2 in the cage. With many metabolic phenotyping systems, CO2 concentrations within the cage can easily reach 0.5%, comparable to an overcrowded seminar room. Because of the high flow rate, CO2 concentrations within the cages of a Promethion Core system will seldom exceed 0.1 – 0.2%. This means that in a Promethion Core system, animals are close to normocapnia (ambient CO2 concentrations). Animals exposed to incipient hypercapnia (excessive CO2 concentrations) can have a panoply of physiological and cognitive effects that may confound otherwise good experimental protocols.

Q: Can Promethion Core be used for gnotobiotic research?

A: Yes, we have modified the Tecniplast Isocage (mouse) to have the same features and performance as our standard mouse cage. The cage is sealed and the incoming and outgoing air flows through a HEPA filter. The isocage enables gnotobiotic and microbiome research. With Promethion Core coupled to our advanced methane analyzer, microbiome production of methane may be quantified. 

Q: Does Promethion Core monitor the environment of the cages? Can we detect external influences that might disturb an experiment or may have caused artifacts in the data?

Our Environmental Sensor Array ESA-1 measures multiple relevant parameters in the environment of the cages. This includes temperature, humidity, barometric pressure, light level, sound level, as well as overall motion in the surrounds of the cages. Taken together, they allow you to easily spot abnormalities in temperature profile, room light cycles, or expected and unexpected access to the cages.

Q: How does Promethion Core handle time changes? I.e. what happens if we have a long recording and everything switches to summer time mid-run?

Our data file format encodes the end time of the recording. All other sample times are calculated from this time stamp. This means that time switches have no immediate impact on the recording. However, all times in the file will appear as if recorded under the new time after the switch.

QWe need to run our animals at thermoneutrality. Is Promethion Core compatible with thermal cabinets? Does Sable offer one?

Our temperature cabinets CAB-8 and CAB-16 have been specifically designed for respirometry applications. Offering a temperature range of 4C to 40C, they stand out with an ergonomic tray design that eases servicing the cages in the cabinet without having to disconnect half the system to top up a food hopper. Built in cage plumbing and mount points for the CGF gas analyzer make installing a system a breeze and retain the small overall footprint.

Q: What is EthoScan?

A: EthoScan is a suite of behavioral analysis tools built into MacroInterpreter. It uses all sensor data from each cage to assign each sample to one of 11 behaviors, creating a fully automatic behavior log. From this log additional summaries like time budgets and a Markov chain analysis can be derived.

Q: Does EthoScan provide time budgets for each behavior? What about locomotory budgets? Can the time budgets be binned, e.g. day vs. night?

A: Yes. Time Budgets and locomotory budgets are a standard feature of the EthoScan analysis results. By default, the “One Click Macro” analyzes the whole file. However, it is possible to customize the macro to run the EthoScan analysis multiple times on subsets of the data (bins). This is useful to differentiate circadian changes in behavior (e.g. day vs. night) as well as temporal and possibly transient changes in behavior due to a treatment.

Q: What is a Behavior Transition Matrix?

A: Once the behavior sequence is determined, it can be statistically analyzed. One simple sequence analysis is to look at the frequency of specific pairs of behaviors given the overall number of behavior transitions in the sequence. When done systematically, the frequencies will completely fill a matrix of all possible behavior pairings. That is each row would contain all transitions of a specific behavior *to* all other behaviors, while each column lists the transitions to a specific behavior *from* all other behaviors. This matrix is the Behavior Transition Matrix.

Note that when the frequencies are interpreted as probabilities, the matrix also forms what is called a Markov Model of each animal’s behavior. By random sampling these models it is possible to generate artificial behavior sequences that have the same statistical properties of behavioral transitions as the real animal.

Q: What is the basis of the Promethion Core food intake measurements?

We use load cell technology, the same technology that is used in laboratory balances. This provides excellent linearity, and we have developed proprietary electronic methods for improving the resolution of this technology to an unprecedented level. Our mass monitors, the basis of our food intake measurements, have a range of 0 – 750 g and a resolution of 0.002g. 

Q: Impressive technology, but does it bring any practical benefits?

The wide mass measurement range allows the load cell technology to monitor food intake, water intake, and rat and mouse body mass measurements. This saves money and time as the mass monitor can be used for all of the above measurements. There is no need to purchase multiple models of mass monitors, and no need to keep track of which type is being used for which application.

The very high resolution translates to detecting micro-intake events, which are invisible to other systems. For example, mice often pause at the food hopper and nibble at food, taking only a few milligrams before moving on. This is a legitimate intake event that is completely missed by systems which can only detect 10 to 20 times that amount. Each micro-intake event represents a decision by the experimental animal to ingest food. 

Q: How do you know whether a food intake event is real, or simply the result of random noise?

The stable food hopper mass is determined prior to the feeding event, and second, an equivalent stable hopper mass is determined after the feeding event. The two masses and their associated standard deviations are compared using a statistical test, and the intake event is only scored if the probability of the mass change having occurred by chance is below a settable threshold, P <= 0.05 by default.

These calculations are done automatically by macros under the full control of the user. Of course, you have full control over all parameters and plenty of technical and scientific support if you have questions.

Q: Do your food hoppers swing from chains, as with some other systems? It seems that would add several seconds of uncertainty to the timing of intake bouts.

Promethion Core food hoppers are rigidly mounted to ultra-precise load cells with no ringing, swinging or instability, giving you precise timing and intake measurements.

Q: Are your food hoppers mounted in large tubes? Would tubes have an unacceptable amount of dead volume for metabolic measurements?

Such tubes certainly distort metabolic response times. Our mass measurement modules are designed to have negligible interior volumes. They have no effect on metabolic measurements. Moreover, at only 1 cm high, they also add no significant height to the cage.

Q: Do your mass measurement devices need a half-day stabilizing prior to starting measurements?

No, you can get reliable data from them immediately as they are based on load cells instead of drifty force transducers.

Q: What binning interval do you use for food intake measurements?

Promethion Core captures, retains, and analyzes the raw food intake data at one second intervals. Only during the final data extraction step may a user defined binning increment be applied. For different binning, the collected data can simply be reextracted then reanalyzed. This gives unprecedented flexibility in food intake analysis.

With other systems, it may be necessary to re-book the metabolic phenotyping center and re-run the animals with a different binning interval at huge inconvenience and expense.

Q: Do you offer full intake pattern analysis?

Our standard analytical macros contain a detailed intake pattern analysis. It sorts detected events into bouts and will provide start time, end time, the amount consumed, as well as the inter-bout interval. In addition, we calculate an index of how forcibly the animal interacted with the hopper. Optionally, bouts can be additionally sorted into meals based on the amount of food consumed as well as timing criteria (e.g. maximum inter-bout interval still considered a single meal).

Since Promethion Core retains all raw data, it is possible to replace the bout/meal sorting with custom algorithms for more complicated use cases. Very determined users could even completely replace the initial event detection with their own algorithms.

Q: I need accurate conversion of food intake masses to energy equivalents. How do you compensate for the variable contribution of hydration to food mass and its effect on energy conversion accuracy?

Promethion Core records the water vapor pressure within the cage. This allows food masses to be corrected for variable hydration levels, yielding more accurate food mass to energy equivalent conversions. No other system offers this capability, which we suspect will soon become a requirement for reproducible research.

Q: Is food spillage/caching a problem? What about different types of diets with different properties?

A: To minimize spillage related errors in intake measurement, we added multiple unique features to our hoppers. Firstly, a crumb tray collects any small spillage right at the grille. Since it is still part of the hopper weight, its weight is not counted as food intake. Furthermore, the front plate is exchangeable, allowing the use of the most optimal grille design for any particular food, whether it be small chow pellets, large chunks or sticky high fat diet. And if you have your own ideas how the optimal food grille looks like, we can easily customize the front plate to nearly any design you can imagine.

Q: Do you have food dispensers for a liquid diet?

A: We do have inserts for the food hopper available that can deliver liquid foods.

Q: How many food sensors can be used on a cage? We would like to perform food choice/preference studies.

A: All of our weight modules are identical and can be used with any type of hopper (food, water, body mass). The standard cage lid offers three slots for weight modules, enough for a simple food choice experiment with concurrent measurement of water intake. All that is needed over a standard complement of cage modules is an extra set of food hoppers. For more demanding studies we offer alternative lids that offer up to four slots for weight modules, two of which can be controlled by food access control doors.

Q:  How does Promethion Core differ from other metabolic or behavioral phenotyping systems?

A:  High-resolution metabolic and behavioral phenotyping is only possible with Promethion Core. High-resolution gas analyzers and pull-mode respirometry enable a high flow rate which delivers high temporal resolution. Thus, only Promethion Core allows you to synchronize the respirometry measurements with activity, telemetry, or optogenetics measurements for a deeper understanding of your research model.  It also is the only system that provides per activity energy expenditure, example, calories burned during a 2-minute run on the running wheel. Optional high-resolution stable isotope and methane analyzers enable bioenergetics and microbiome studies respectively. 

Promethion Core is the only system with the performance stability to conduct long experiment runs >2 weeks and longitudinal studies over the lifetime of the rodent. This is done by routine water vapor correction.

The modern and compact design means that up to 16 mouse cages can be used in a single environmental cabinet (other systems are limited to 12 mouse cages). Furthermore, our environmental cabinet is engineered specifically for metabolic phenotyping cages so it is easy to use and, most importantly, does not produce the respirometry artefacts that plague standard environmental cabinets. The gas analyzers are attached to either the environmental cabinet or the cage rack, making it the most ergonomic and space-efficient system on the market. 

Q:  How rapidly does Promethion Core sample metabolic data (VO2, VCO2, RER, EE) from multiple cages?

A: Our multiplexed systems sample metabolic data for all cages in 4, 8, or 16 cage systems in as little as 2.5 minutes, independent of the number of cages or the length of tubing from the cages to our analyzers. This provides you the temporal resolution to correlate changes in metabolism with changes in activity.

Q: How frequently does Promethion Core sample non-metabolic data?

A: Once per second. This gives you unprecedented detail into food and water intake, plus body mass, wheel running, animal position, and coarse and fine activity.

Q:  Is the running wheel an external add-on to the cage?

A: No, the optional running wheels are internal to the mouse cage. The internal mounting minimizes the cage height, enabling the fitting of up to 16 mouse cages in an environmental cabinet.  It additionally prevents the risk of cage leaks that could be detrimental to metabolic measurements. An optional programmable wheel stop module mounted on top of the cage lid can be used to control the running wheel availability dynamically during an experiment.

Q: Is it true that Promethion Core doesn’t use desiccants?

A: True. By understanding the simple physics behind the effect known as water vapor dilution, Promethion Core is able to do away with gas scrubbing. Our accurate water vapor sensors allow us to directly measure the amount of water vapor present in the cage air and mathematically account for it. After all, no one enjoys changing out scrubber columns every three days. This allows continuous recordings of over 10 days. As an additional bonus, this allows Promethion Core to calculate the total water loss of the animal, making it the only system that can measure all components of the water balance of the animals.

Q:  Why are Sable Systems gas analyzers unique?

A: When Sable Systems set out to design the best respirometry systems on the market it became clear to us that analyzers made for process control are not good enough. So, we designed our own from the ground up, specifically optimizing them for flow through respirometry. Their uncompromising stability, low noise levels and high resolution make them best in class. Widely regarded as some of the best analyzers on the market, our customer list has grown to include climatologists and major research organizations like NIST and NASA.

Q: How much space does the Promethion Core system require? 

A: It obviously depends on the number of cages in the overall system. Up to 16 mouse cages can be housed on a single wire rack with dimensions 60″W x 24″D x 72″H when not using environmental cabinets. The CGF gas analyzer is mounted on the side of the rack, increasing the overall footprint to 70”W x 24”D.  

When using environmental cabinets, the dimensions of a CAB-8 (capacity 8 cages) are 32”W x 32”D x 78.5”H, while the dimensions of a CAB-16 (up to 16 cages capacity) are 66”W x 32”D x 78.5”H. Again, the CGF gas analyzers are mounted at the side of the cabinets giving overall footprints of 42”W x 32”D and 76”W x 32”D, respectively.

Q: How much ongoing maintenance is needed for Sable gas analyzers? What disposable items are there?

The system itself has very few disposable items. Mainly, filters and the O2 sensors. Lifetime of the sensors are variable, with the minimum observed being 18 months and somewhat depending on the usage of the system. Service agreement subscribers get their O2 sensors exchanged annually as part of the service package.

Additionally, depending on the frequency of calibration, gas tanks might need to be reordered. For most customers this is likewise an annual (or less frequently) procedure when following the recommended calibration interval of every two weeks.

Q: How long does it take to set up an experiment on Promethion Core systems?

Experienced operators can set up a 16-cage system in less than 1 hour from start to finish when starting from a disassembled state (e.g. after components come back from cage-wash). For time critical applications, given enough spare modules, it is possible to pre-assemble and prepare cage tubs ahead of time, allowing fast change-over times of ~15 min for a 16 cage system.

Q: Is the Promethion Core system compatible with Optogenetics?

A: Optogenetics does not interfere with the normal function of our other sensors and gas analyzers. While the cages have not been specifically designed for Optogenetics experiments, we do offer specialized lids that minimize the risk of entanglement or breaking of the glass fibers.

Q: What are the advantages of the Promethion RoomCal system?

A: Promethion Room Calorimetry provides three main advantages over more conventional systems. 

Firstly, our patent pending “Background Baselining” approach ensures seamless room data while allowing for very high rates of incurrent air measurements as well. This relaxes the need for very tight stability control of the incurrent air, a requirement often necessitating the addition of empty “buffer rooms” taking up even more valuable lab space. Background baselining also allows us to use a very simple “room correction” algorithm.

Secondly, Promethion measures water vapor content of the air and corrects it mathematically. Not only does it get away without large amounts scrubber chemicals, in certain circumstances it is the only way to correctly account for water vapor. On cold winter days chilling dehumidifiers can easily become ineffective or worse active humidifiers (Melanson EL, et. al., Am J Physiol Regul Integr Comp Physiol 2010). And since we have measured it, why not calculate the evaporative water loss of the subject?

Lastly, we use pull-mode respirometry throughout, which slightly simplifies room construction or even allows to convert existing conventional rooms into metabolic rooms in some cases.

In summary, Promethion Room Calorimetry makes the setup and operation of a room calorimetry straight forward.

Q: Does Sable Systems build the room?

A: While we are normally not involved in the project management for the rooms themselves, Sable has the expertise to consultant with local project teams. We also have a partner network of trusted independent consultants that can assist with the projection and construction of a metabolic room.

Q: How can a room calorimetry system be validated?

A: Promethion Room Calorimetry systems can be validated with either gold standard method – propane or alcohol burns, as well as gas blending. In fact, we recommend regular validation of the system as per RICORS 1.0 (Chen KY, et. al. Obesity 2020).

Q: Can the room calorimetry system be used with other modalities like masks or hoods?

A: Yes, the flow range of our room calorimetry instrumentation allows multiple modalities. Simply swap out your room with a canopy, reduce the flow rate accordingly, and you are good to go. For masks, an additional mixing chamber can be added to average out breath-by-breath fluctuations.

Q: What flow rate is the system using?

A: Our flow generator FG-250 supports flow rates between 40 – 250 LPM. 

Q: How do you correct the slow response time in a large room?

A: Our patent pending Background Baselining approach allows us to seamlessly remove all baselining interruptions from the room signal prior to the room correction. This in turn allows us to use a simple transformation called the “z-transformation” to correct the low pass effect of the large room volume to flow rate ratio. Whereas the response time of the room to a step change in concentrations (e.g. an exercise bout) is in the order of hours, room correction makes it possible to detect changes on the scale of minutes.

Q: What is Promethion Live?

A: Promethion Live is embedded software that allows you to easily set up your metabolic and behavioral studies for data acquisition, real-time study monitoring with cohort analysis, graphical visualization of results, error detection, and data export.

Q: What is MacroInterpreter?

A: MacroInterpreter is our stand-alone analysis program used to analyze the raw data collected by Promethion Live. Analysis is driven by analytical scripts (macros) allowing to code custom analyses as well as run standard scripts provided by us that cover the most common usage scenarios. In addition, MacroInterpreter allows ad-hoc manual analysis steps that can be recorded to form the basis of new analytical macros.

Q: What is ExpeData?

A: ExpeData is a data acquisition and analysis program used to record and analyze data from our Classic Line products. It is the forerunner of MacroInterpreter and shares many of its features. 

Q: If I upgrade the system at a future date, do I need to pay additional per-sensor licensing fees for the additional sensors in the system?

A: We do not charge per-sensor licensing fees.

Q: I have several associates and graduate students, and I would like them all to have unrestricted access to the analytical environment, Expedata/MacroInterpreter. What is the licensing fee for additional copies of ExpeData/MacroInterpreter?

A: There are no licensing fees for additional copies of Expedata/MacroInterpreter used by personnel in the same laboratory.

Q: If we decide to upgrade our Promethion Core system, do we have to purchase aggregators or computer cards to handle the additional sensors?

A: Promethion Core does not use any hardware aggregators or computer cards at all. In fact, Promethion Core comes with its own embedded, network enabled computer, which makes upgrading fast and effortless. Access to the system is possible via standard web browsers from all computers connected to the same network. 

Q: Do I need a powerful computer to acquire Promethion Core data?

A: Promethion Core has an integrated computer that operates the system via Promethion Live software. Promethion Live is accessed through any browser from any computer on the same network (direct connection, WiFi, or both). Promethion Live acquires, stores, processes, and reports the data independent of the computer used to access the system. No external computer is needed for ongoing acquisition of the data.

Q: Do I need a powerful computer for data analysis?

A: For data analysis using the analytical macros, we recommend a multi-core computer with at least 8 GB of RAM and a supported 64-bit Microsoft Windows operating system (Windows 10/11).  

Q: What happens if there is a power outage during data acquisition?

A: If the CGF gas analyzer still has power (e.g. from an uninterruptible power supply), acquisition of data is not affected at all even if the computer used to access the system goes down. The same goes if an automatic operating system update reboots the access computer.

If the CGF is out of power, data acquisition terminates, but will have all data written to the internal storage of the CGF right until the point of power failure. Once power comes back, the available data can be restored and used for analysis. Note that data acquisition will not automatically restart after power on. 

Q: How to send items for repairs

A: The best way to initiate a repair or evaluation is to contact our Technical Support team. Please note that we can only accept shipments that have been authorized by us, are properly decontaminated if applicable, and have an RMA number assigned. Please reference the RMA number on all items returned.

Q: Does Sable offer Service Agreements?

A: For our Promethion Core products, a Total Performance Guarantee is offered. It includes an extended warranty as well as an annual service visit. preventative maintenance, additional training, and software update; rapid parts delivery; and free of charge repair or replacement of system parts.

Q: Does Sable Systems provide additional training over what we received at the time of the system installation? What about my specific applications? Is it possible to get training at my location?

Yes. While the Sars-Covid pandemic had suspended training operations at our HQ in Las Vegas, we are back to our typical schedule of semi-annual training courses. These courses offer advanced insight into the theory, use, and application of our respirometry equipment. The course occurs over 3-4 consecutive days.

For more specific applications or special requests, we can offer from customized remote training/consulting to a full-blown custom training course or workshop at the customer location. Please contact our Technical Support or Sales teams for details.

Q: Does Sable Systems provide Macro customization or Data Analysis services?

A: Macro requests or customization work less than 5 hours is complimentarily and included as part of the system installation or service contract. For larger requests, we offer hourly billed consulting services.

Q: Can telemetry be added to the system? What parameters are available?

A: Promethion Core is compatible with multiple telemetry systems from different vendors, some of which directly integrate with Promethion Core for a seamless experience. Various probes offer the measurement of core body temperature and heart rate.

For telemetry probes that use magnetic switches to conserve energy, modified Promethion Core components are available that are functionally equivalent, but avoid the use of magnets for other purposes (MM lid mount, wheel counter).

Q: What is the spacing between the infrared beams in your open field array?

A: 1 cm. That is the densest beam spacing in the metabolic phenotyping field. Because the open field monitor contains considerable built-in intelligence (without requiring connection to cards inside a computer!) it is capable of analyzing the shape of objects and calculating their centroid position, which it does to an effective resolution of 0.25 cm.

Q: Do you have both mouse and rat models of the open field array?

A: Yes, and the beam spacing is identical for each model, though the rat model is physically larger. This means that the rat open field array can be used to monitor either mouse or rat cages, saving money without sacrificing resolution.

Q: Does the open field array monitor beam breaks, or actual position?

A: Both. You have a full second-by-second record of the animal’s position in the cage, and any beam-breaks that it causes.

Q: Can you distinguish coarse and fine activity?

A: Yes. Coarse activity is primarily directed pedestrian locomotion, while fine activity is a more sedentary group of behaviors, including grooming and scratching. Promethion Core distinguishes between coarse and fine activity and analysis parameters can be fine-tuned. Because the system records all of the data in one second intervals, there is total analytical flexibility to create data sets that show the practical effect of incremental changes in the coarse/fine distinction.

Q: Can I export the position data to other programs in order to create heat maps or do other, more detailed analyses?

A: Yes. All raw and processed data acquired by Promethion Core can be exported, either directly to Excel or as a .CSV file. This allows you to use virtually any data analysis environment for further processing of the data. One popular choice is the CalR web application ( for which our standard macros create a specially formatted CSV output file that can be directly uploaded in CalR.

For other select languages like R and Python our data scientists have provided as-is, open-source import packages that can read the SSCF Promethion Core binary file format directly. Please contact our Customer Support team, if interested.

Q: Can Promethion Core be used to assess the metabolism of mice during induced exercise?

A: Yes, our mouse metabolic treadmill is designed to integrate with Promethion Core. It can be used instead of a standard metabolic cage. Treadmill protocols are stored on and executed by the treadmill control box. Promethion Live acquires respirometry data. We also provide treadmill specific macros for data evaluation (example, VO2max macro). 

Q: Can VO2max studies be performed on the treadmill?

A: VO2max studies may be performed with the treadmill. To induce running, the treadmill has 3 programmable stimuli-auditory, visual, and electric shock as well as a manual stimulus which is a push brush. The electric shock grid intensity may be adjusted to optimize the stimulus intensity.

Q: Does the treadmill include video monitoring of the mouse for gait analysis?

A: While not including a camera itself, the treadmill has been designed with video compatibility in mind. Both the front side wall and the top lid are clear, enabling users to acquire high quality video with their own camera. Different user replaceable backgrounds can be installed in the back wall to enhance the contrast of the mouse or provide a regular grid behind the animal aiding in image registration and camera calibration.

Q: How does Promethion Core account for water evaporation? Does this introduce an error in water intake figures?

A: No error is introduced from evaporation because the intake measurement is strictly differential. A disturbance of the hopper or dispenser is sensed and the mass change from before to after the disturbance is measured. Thus, slow changes in hopper or dispenser mass are ignored. This makes Promethion Core’s intake measurement technique more accurate than simple weighing of the hopper or dispenser at intervals.

Q: If the temperature of the cage increases, gas at the top of the water dispenser can expand and force drops of water from the dispenser spout. Are drops incorrectly counted as intake events because they must cause a disturbance in the mass measurements?

A: By default, intake events must last longer than a user-settable duration in order to be counted as true intake events. The disturbance caused by a drop falling from the dispenser, which is a rare event, is extremely brief and does not resemble a genuine intake event, so it is ignored.

Q: How often does the water need to be refilled? What is the capacity of the dispenser?

A: A mouse water bottle holds up to 125mL of liquid. This amounts to about >2 weeks for average consumption. 

Q: How prone are the water bottles to clogging?A: Our sipper tubes have been designed without any moving parts like ball bearings. The sipper internal diameter is optimized to prevent dripping even without a mechanical plug. 

Q: How do you sense wheel rotation?

A: Similarly to a bicycle odometer. A magnet mounted on the wheel when passing a stationary reed switch creates a voltage drop that is detected as a pulse. Each count then amounts to one rotation of the wheel, which can be converted into a distance using the known circumference of each wheel.

Q: Does the reed switch have a limited lifetime?

A: The estimated lifetime of our Reed switch is at least 1,000,000,000 (10^9) counts. At an average running speed of 2 counts per second, this equals 15.8 years of continuous running. On the other hand, the wheel magnet will lose its strength over time from the heat of cage washing. Sometimes as short as 6 months intervals in heavy use scenarios. However, they are easily and economically replaced. 

Q: Aren’t optical methods better in terms of reliability and lifetime?

A: We decided against using optical methods because they are less reliable. First, they are vulnerable to dirt buildup and scratches in the cage tub that block or otherwise interfere with the optical beam. Second, their alignment is critical to performance but they are easily knocked out of alignment. 

Q: Are wheel rotations easily converted to actual distance run and running speed?

A: Our analysis environments (MacroInterpreter and Promethion Live) can quickly and automatically accumulate wheel revolutions and multiply them by the running wheel circumference to yield cumulative distance traveled. The software also divides distance by time, providing running speed.

Q: Do you have a way of automatically prevent the running wheel from turning?

A: Yes, we have an automated wheel-stop for our mouse cages. The wheel can be locked on a schedule.