Seventeen week old male and female mice are screened for alterations in plasma concentrations of corticosterone, testosterone, and androstenedione. Blood is collected retro bulbar from narcotised mice (isoflurane). Plasma is prepared by centrifugation and stored at -20° C.
The sample preparation and LC-MS/MS measurement is fully described in our publication in Nature Protocols:
For the analysis 50 µL mouse plasma is necessary. Quantification is done by HPLC (Shimadzu Prominence) and Triple Quadrupol Mass Spectrometer (4000 QTrap, ABSciex) in the Genome Analysis Center (GAC).