Feeling Hormonal

A few months ago, we shared an initial update about our project funded by SeaWorld Busch Gardens Conservation Fund looking into Steller sea lion pregnancy hormones. In that blog (read it here), we showed the multi-step process of taking a donated fecal sample and preparing it for hormone quantification. In short, this process involved removing water, and sifting out artifacts from prey items. Finally, a subset of the fecal sample is eluted in ethanol to extract hormones into liquid, which can then be frozen until analysis.

Now the real magic begins!

We can take the mixture of hormones we extracted into a liquid, and enumerate each fecal sample’s progesterone (P4) level using a commercial assay kit.

All the necessary reagents (e.g. ingredients) needed to detect and quantify progesterone in a sample.

While a bit more complicated, this kit basically calculates the progesterone concentration in our samples by comparing the light reflected in sea lion fecal samples to values from samples of known progesterone concentration a.k.a. standards. This process is called chemiluminescence (color change resulting from a chemical reaction that can be measured by light) and is possible through a series of carefully calculated chemical reactions… so lots and lots of math and pipetting.