Method for measuring protease activity

A method for measuring protease activity, which comprises the steps of:

• (1) bringing a biosample containing a protease into contact with a crosslinked and/or substantially water-insoluble thin membrane that is formed on a support surface and contains at least one colorant selected from the group consisting of an emulsion-dispersed colorant and a solid-dispersed colorant and a protease substrate;
• (2) washing the thin membrane with an aqueous medium and detecting traces of digestion formed on the thin membrane by the action of the protease;
• and
• (3) staining the biosample on the thin membrane.

A method for measuring protease activity, which comprises the steps of:

• (1) bringing one of two or more substantially continuous slices of a biosample into contact with a crosslinked and/or substantially water-insoluble thin membrane that is formed on a support surface and contains at least one colorant selected from the group consisting of an emulsion-dispersed colorant and a solid-dispersed colorant, wherein said colorant is not a fluorescent colorant, and a protease substrate;
• (2) bringing another slice of said slices into contact with a crosslinked and/or substantially water-insoluble thin membrane that is formed on a support surface and contains at least one colorant selected from the group consisting of an emulsion-dispersed colorant and a solid-dispersed colorant, wherein said colorant is not a fluorescent colorant, a protease substrate, and a protease inhibitor;
• (3) washing the thin membranes with an aqueous medium and detecting traces of digestion formed on the thin membranes by the action of the protease;
• and
• (4) comparing the traces of digestion on the thin membrane used in the step (1) with the traces of digestion on the thin membranes used in the step (2).

A method for measuring protease activity, which comprises the steps of:

• (1) bringing one of two or more substantially continuous slices of a biosample into contact with a crosslinked and/or substantially water-insoluble thin membrane that is formed on a support surface and contains at least one colorant selected from the group consisting of an emulsion-dispersed colorant and a solid-dispersed colorant and a protease substrate;
• (2) bringing another slice of said slices into contact with a crosslinked and/or substantially water-insoluble thin membrane that is formed on a support surface and contains at least one colorant selected from the group consisting of an emulsion-dispersed colorant and a solid-dispersed colorant, a protease substrate, and a protease inhibitor;
• (3) washing the thin membranes with an aqueous medium and detecting traces of digestion formed on the thin membranes by the action of the protease;
• (4) staining the biosample on the thin membranes;
• and
• (5) comparing the traces of digestion on the thin membrane used in the step (1) with the traces of digestion on the thin membrane used in the step (2).