metabolic phenotyping

Measuring metabolic rates in a stress free home cage environment is great for the experimental animal, but can't be implemented if quantitative urine and feces collection is also required. Metabolic cages exist that are specially designed for accurate collection of urine and feces, and as this blog post shows, can easily be adapted for metabolic measurement using a Promethion pull-mode metabolic phenotyping system.

Data from a metabolic phenotyping system can be rigidly determined by the parameters entered at the time of the experiment (as with legacy systems), or the data can be a rich mine of information, with complete post-hoc analytical flexibility (as with Promethion). The latter approach allows extraction of experimental data, the need for which was not anticipated at the time of the study. This can save serious amounts of time and money - apart from producing better science.

Correlating activity and energy expenditure in "legacy" metabolic phenotyping systems is almost impossible. However, the new Promethion-C parallel, continuous metabolic phenotyping system makes it easy. We demonstrate this by extracting data on the metabolic cost of a specific activity from a Promethion-C continuous, parallel metabolic phenotyping system - data that normally requires a treadmill, a skilled human operator, extensive training, and a lot of stress for all concerned. And we conclusively prove that we can do it accurately, on multiple animals simultaneously, and without stress.

Multiplexing metabolic signals causes significant data distortion. This post explains how, and gives you access to an amazing, interactive tool for exploring the metabolic data distortions produced by this practically universally-used technique!

A funny thing happened on my way to helping a colleague make sense of the specifications of a metabolic phenotyping system. There were many strange things to mull over. Not the least of these were oxygen and carbon dioxide analyzer accuracy specifications that appeared to be the product of smoke, mirrors, and absinthe-infused coca tea sipped through a crazy straw.

Want to measure food uptake by your experimental animal, such as a rat or mouse? There's the easy wrong way and the even easier right way (the latter with a smidgeon more tech). Plus a tickler.

Sometimes (almost always, if you're a researcher) you just can't get too much data. Click above to see just a subset of the data you can get in a day (and night) from just one busy little mouse.

Just a quick post to let the teeming multitudes (all three of you) know that Respirometry.org's long stasis is at an end. I'll be posting new content on a regular basis, much of it available nowhere else. I'll be blogging muchly about Promethion, a new metabolic measurement system for biomedical researchers, but also on other topics.

Anyone who has read Chapter 13 of my book knows that I have a hobby-horse: the accuracy of metabolic rate measurement, especially in the metabolic phenotyping systems that are so widely used in the biomedical field. Now I've taken steps to make some of my (and others'!) misgivings known. 

It's really frustrating to watch otherwise capable researchers in the biomedical field flock to use the same black-box metabolic screening systems that others used before because, well, everyone uses them.