Mass spectrometry assay as an alternative to the enzyme-linked immunosorbent assay test for biomarker quantitation in ecotoxicology : application to vitellogenin in Crustacea (Gammarus fossarum)
La spectrométrie de masse comme alternative à l'ELISA pour la quantification de biomarqueurs en écotoxicologie : application à la vitellogénine chez les crustacés (Gammarus fossarum)
Résumé
Vitellogenin (Vg)is a widespread biomarker for measuring exposure to endocrine disruptors. Vg quantification is usually done by using the ELISA test (enzyme-linked immunosorbent assay). Since this test is specific to a target protein, it can rarely be used with other species due to low cross-reactivity across species. Therefore alternative analytical methods have to be considered as the development of a specific and sensitive ELISA test for each new target is time-consuming and may prove unsuccessful. This paper focuses on the development of a quantitative assay by liquid chromatography tandem mass spectrometry (LC-MS/MS) of vitellogenin in an invertebrate (Gammarus fossarum) for which no ELISA kit is available. The linearity of the method was within the concentration range 2.525,000pg/mL and the limit of detection was estimated at 0.75 pg/mL of Vg. This method has been demonstrated to be an alternative to existing immunological methods for quantifying Vg in invertebrates due to its greater sensitivity, specificity and reproducibility (intra- and inter-assay below 15%). This assay was applied for Vg determination in female G. fossarum following exposure to a known endocrine disruptor, methylfarnesoate, in crustaceans. The availability of a quantitative G. fossarum LC-MS/MS assay should open the way for further studies to evaluate xenoestrogen effects in aquatic male G. fossarum.