Nitroblue tetrazolium

Formula : C40-H30-N10-O6.2Cl
CAS : 298-83-9 

Colorless to yellow dye that is reducible to blue or black formazan crystals by certain cells; formerly used to distinguish between nonbacterial and bacterial diseases, the latter causing neutrophils to reduce the dye; used to confirm diagnosis of chronic granulomatous disease.

Nitrocefin

Formula : C21-H16-N4-O8-S2
CAS : 41906-86-9 

Chromogenic cephalosporin used for detection of beta-lactamase activity; Cefinase is name for nitrocefin on paper disc.