Protease Assay Kit -

The Protease Assay Kit (sufficient for 250 assays) offers a simple non-radioactive method for routine assays monitoring the presence of contaminating proteases in protein samples and following the isolation of proteases.Casein is used as substrate in the assay kit,and its breakdown is measured by a simple colorimetric protein-dye binding method.Degradation of casein by a protease causes a decrease in absorbance at 595 nm.The assay kit can also be custom modified for determining cofactor dependence,pH or temperature optima,and potential regulation by a protease activator or inhibitor.For instance,including 5 mM or 5 mM Ca2+ in the assay buffer allows one to determine the activity of calpain I or calpain II,respectively.A protease control (trypsin) is included in the kit,allowing users to perform a positive control assay.A set of 10x concentrated buffers from pH 6 - 8 are provided for determining pH vs.activity profiles of the proteases of interest.Assays can be performed in microplates and measured by a microplate reader.Results can be obtained in less than 30 min.Assay conditions for a particular protease can be easily optimized for maximal sensitivity.