Method comparison of dipeptidyl peptidase IV activity assays and their application in biological samples containing reversible inhibitors

► Commercial assays are available for measuring DPPIV activity in biological samples. ► Gly-Pro based substrate comparison with colorimetry, fluorescence and chemiluminescence. ► Such comparison was never executed before. All methods performed well. ► DPPIV inhibition is usually underestimated in samples with reversible inhibitors. ► One assay was elaborated to estimate residual DPPIV activity in these samples.