ABSTRACT
Objective To establish a chromogenic assay for blood-plasma collagenase Ⅳ in order to evaluation the reference range of collagenase Ⅳ in the plasma of healthy individuals.Methods The assay was based on measurement of terminal amino group with succinylated gelatin as substrates and TNBS as chromogenic reagent.The optical density of each reaction was determined at 405 nm using a Sunrise microplate reader.Chromatographic and detection conditions were optimized and performance of the methed was evaluated by recovery experiments and precision experiments.It was compared with ELISA.The levels of collagenase Ⅳ in 112 health persons'plasma were determined and the data were analyzed by SPSS statistical software.Results The whole determing time was within 1.5 h,the linear range of this method was 1.5-10.0 mg/L,and the minimum detection limit was 0.965 mg/L.They were well correlated with ELISA results (R~2=0.999 7,P＜0.01).The within-run CV was less than 3.16%and between-run CV was less than 9.81%.The 95%confidence interval of collagenase Ⅳ in healthy plasma was 33.38-49.80 mg/L.Conclusion This chromogenic assay for blood-plasma collagenase Ⅳ can be used for measurement of collagenase Ⅳ in blood-plasma and the reference range of collagenase Ⅳ in healthy plasma was established.