An important consideration in the study of hormones is their variability in response to internal and external stimuli, which can provide insight into a variety of biological processes of interest to conservation and management. This essential variability is, of course, what makes these molecules valuable to study, but it adds interesting complications to the sample collection. Traditional blood samples can be difficult if not impossible to collect from large, free-range, terrestrial or aquatic mammals. Furthermore, even if you can catch your subjects, the very act of collecting invasive samples like blood can stress the animal and change the hormone profile you’re trying to determine.
Fortunately, many hormones can be reliably measured in non-invasive sample types such as feces, urine, saliva, mucus, hair, nails, baleen, feathers etc. Studies have shown1-3 that many hormones and messenger molecules retain the same relative concentration trends in these sorts of non-invasive samples as are observed in blood. In other words, if a treatment or environmental stressor raises the level of target molecule in the blood, the amount measured in feces or saliva or respiratory vapors etc. will increase proportionally. Additionally, collection and extraction protocols for many different sample matrices have been verified and published, allowing researchers access to data they might not otherwise be able to collect.
For example, E.A. Burgess et al.1 from the John H. Prescott Laboratory at the New England Aquarium recently published using five different Arbor Assays EIA kits (Testosterone, Progesterone, Estradiol, Cortisol and Aldosterone) in a paper evaluating the efficacy and efficiency of various methods of collecting and storing samples from whale blow. Collecting blow samples is non-invasive and could potentially be used with a wide variety of both captive and wild cetaceans. This is certainly a significant boon to researchers interested in reproduction or stress markers in native whale populations.
Working creatively to get the information you need from the samples you have access to can be a central part of experimental design. Critical to these types of experiments are assays that are sensitive enough to allow for the measurement of target hormones in a wide variety of matrices, preferably with very small sample sizes. Arbor Assays kits are designed with these needs in mind. We are always working collaboratively so that our customers can get the most from their small volume or low concentration samples.
- A. Burgess et al. (2016) Get the most out of blow hormones: validation of sampling materials, field storage and extraction techniques for whale respiratory vapour samples; Conserv. Physiol. Vol.4 issue 1
- J. Sheriff et al. (2010) Assessing stress in animal populations: Do fecal and plasma glucocorticoids tell the same story; Gen. Comp. Endocrin. 166 614
- E. Hunt et al. (2014) Baleen hormones: a novel tool for retrospective assessment of stress and reproduction in bowhead whales (Balaena mysticetus); Conserv. Physiol. Vol2 issue 1