EPA Science Inventory

An inter-laboratory study on the variability in measured concentrations of 17Beta-estradiol, testosterone and 11-ketotestosterone in white sucker: implications and recommendations

Citation:

Feswick, A., G. Ankley, N. Denslow, L. Ellestad, M. Fuzzen, K. Jensen, K. Kroll, A. Lister, D. MacLatchy, M. McMaster, E. Orlando, M. Servos, G. Tetreault, M. Van Den Heuvel, AND K. Munkittrick. An inter-laboratory study on the variability in measured concentrations of 17Beta-estradiol, testosterone and 11-ketotestosterone in white sucker: implications and recommendations. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY. Society of Environmental Toxicology and Chemistry, Pensacola, FL, 33(4):847-857, (2014).

Description:

Endocrine-disrupting chemicals (EDCs) are exogenous substances that can lead to impacts on the reproduction of fish sometimes by altering circulating concentrations of 17â-estradiol (E2), testosterone (T) and 11-ketotestosterone (11-KT). Common methods to measure steroids in plasma samples include radioimmunoassays (RIAs) and enzyme-linked immunosorbant assays (ELISAs). This paper examines variability in E2, T and 11-KT in eight laboratories measuring reference and pulp mill effluent-exposed white sucker (Catostomus commersoni) plasma. We examine the contribution of assay type (RIA vs ELISA), standardized hormone extraction, location of values on the standard curve (upper and lower limits), and other variables on the ability to distinguish hormone levels between reference and exposed fish, and the impact of these variables on absolute quantitation of hormones in different laboratories. Of the eight participating laboratories, seven out of eight and seven out of seven correctly found the differences between sites for female E2 and female T, and seven out of seven and four out of five correctly found no differences between male T and male 11-KT, although the absolute values varied by a factor of 10-, 6-, 14- and 45-fold, respectively. Within laboratory intra-assay variability was generally acceptable and below 15%. Factors contributing to inter-laboratory variability included calculation errors, assay type, and methodology. Based on the inter-laboratory variability detected, we provide guidelines and recommendations to improve accuracy and precision of steroid measurements in fish ecotoxicology studies.

Purpose/Objective:

Endocrine-disrupting chemicals (EDCs) are exogenous substances that can lead to impacts on the reproduction of fish sometimes by altering circulating concentrations of 17β-estradiol (E2), testosterone (T) and 11-ketotestosterone (11-KT). Common methods to measure steroids in plasma samples include radioimmunoassays (RIAs) and enzyme-linked immunosorbant assays (ELISAs). This paper examines variability in E2, T and 11-KT in eight laboratories measuring reference and pulp mill effluent-exposed white sucker (Catostomus commersoni) plasma. Of the eight participating laboratories, seven out of eight and seven out of seven correctly found the differences between sites for female E2 and female T, and seven out of seven and four out of five correctly found no differences between male T and male 11-KT, although the absolute values varied by a factor of 10-, 6-, 14- and 45-fold, respectively. Within laboratory intra-assay variability was generally acceptable and below 15%. Factors contributing to inter-laboratory variability included calculation errors, assay type, and methodology. Based on the inter-laboratory variability detected, we provide guidelines and recommendations to improve accuracy and precision of steroid measurements in fish ecotoxicology studies.

Record Details:

Record Type: DOCUMENT (JOURNAL/PEER REVIEWED JOURNAL)
Completion Date: 06/20/2014
Record Last Revised: 06/20/2014
Record Created: 06/20/2014
Record Released: 06/20/2014
OMB Category: Other
Record ID: 279061

Organization:

U.S. ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF RESEARCH AND DEVELOPMENT

NATIONAL HEALTH AND ENVIRONMENTAL EFFECTS RESEARCH LAB

MID-CONTINENT ECOLOGY DIVISION