The Endocrinology Lab provides diagnostic services to zoos, universities and conservation organizations at minimal cost. The Lab has analyzed samples from animals at over 100 accredited zoos, universities and conservation organizations across the country. Hormone assessments have diagnosed pregnancies, evaluated female reproductive cycles, and monitored levels of stress hormones in numerous species. The Lab also maintains close collaboration with the AZA Reproductive Management Center to determine whether contraception is effectively suppressing reproductive cycles.

Before sending samples, please e-mail Dr. Corinne Kozlowski to confirm assay availability and sampling procedures.


We currently offer assays for the following hormones:

  • Cortisol
  • Corticosterone
  • Estradiol
  • Progesterone
  • Testosterone

Other assays may be available upon request. Please inquire, and we will try to meet your needs.


Serum or Plasma Assays:

  • $14 ($12 discounted rate for batches of 20 or more)
  • $150 Species Validation (one-time charge)

Fecal, Urine or Egg Yolk Assays:

  • $17 ($15 discounted rate for batches of 20 or more)
  • $200 Species Validation (one-time charge)

Price includes analysis of all samples in duplicate and assay of dilutions if required. Radioimmunoassays and enzymeimmunoassays are extensively tested for precision and reproducibility. Species validation includes linearity and recovery studies.

Sample Collection

Our instructions include information about sample collecting, storage and shipment, as well as a submission form. We strongly advise contacting the Lab before sending any samples, because your specific needs—such as frequency of collection—may vary depending on species and the purpose of the analysis.

Samples should be shipped overnight on dry ice or freezer packs to:

Corinne Kozlowski, Ph.D.
Saint Louis Zoo Veterinary Hospital
1 Government Drive
Saint Louis, MO 63110
Phone: (314) 646-4762
Fax: (314) 646-5534