A method to detect proteinase activity using unprocessed X-ray films

Anal Biochem. 1991 Feb 15;193(1):20-3. doi: 10.1016/0003-2697(91)90037-t.

Abstract

Routine assays to detect proteinases in biological samples are generally tedious and time-consuming. To expedite the recognition of proteinases, we have developed an assay utilizing the gelatin on the surface of an unprocessed Kodak X-Omat AR film as the proteolytic substrate. A positive reaction is indicated by a clear zone on the film after it has been rinsed with running water. This proteinase assay has been found to be inexpensive, rapid, and simple. Besides its ease of use, this assay has been found to be quantitatively reproducible with a well-defined endpoint. More importantly, this assay method is applicable to a variety of proteolytic enzymes under diverse pH (5-8.5) and salt conditions (up to 5 M NaCl) and has a sensitivity similar to that of azocoll. Since the assay does not require sophisticated equipment, it is useful as a general laboratory procedure.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Azo Compounds
  • Bacillus subtilis / enzymology
  • Collagen
  • Coloring Agents
  • Endopeptidases / analysis*
  • Endopeptidases / metabolism
  • Gelatin
  • Hydrogen-Ion Concentration
  • Methods
  • Sensitivity and Specificity
  • Sodium Chloride
  • Substrate Specificity
  • Temperature
  • X-Ray Film*

Substances

  • Azo Compounds
  • Coloring Agents
  • Sodium Chloride
  • Azocoll
  • Gelatin
  • Collagen
  • Endopeptidases