Practice question

Luciferase oxidizes luciferin in presence of ATP and oxygen to produce bioluminescence, emitting photons quantified by luminometer rather than colorimetric absorbance. This chemiluminescent system generates light through excited state decay, offering high sensitivity with low background. Horseradish peroxidase with TMB and alkaline phosphatase with pNPP create colored products for spectrophotometric reading. Green fluorescent protein fluoresces intrinsically but lacks enzymatic turnover. Hence luciferin-based detection represents true light emission, widely applied in reporter assays, high sensitivity ELISA variants and ATP quantification improving dynamic range substantially.