The test uses formyl dehydroepiandrosterone piperidine (FDP) as a stress marker. FDP is formed by the reaction of acrolein with protein amino groups. The test uses the reaction of FDP with 4-nitro-phthalonitrile heated in the presence of calcium chloride. The resulting 4-amino-phthalonitrile exhibits significant fluorescence and can be monitored. The method is much cheaper than presently used immunoassays.

RIKEN news release, october 26, 2016