The IDO1 Cellular Activity QuickDetect^TM Supplements are designed to complement the hIDO1-HEK293 Recombinant Cell Line (BPS Bioscience #60532) or other IDO1-expressing cell lines. This kit contains the cell culture medium supplements necessary for activation of IDO1 and for the analysis and detection of Indoleamine 2,3 dioxygenase 1 (IDO1)-catalyzed conversion of L-tryptophan (L-Trp) to Kynurenine (Kyn). The supplements and the detection reagents, when used as described, allow for indirect measurement of Kyn levels by analyzing absorption at 480 nm.