A turbidimetric method for measuring the activity of trypsin and its inhibition

Michael B. Walker, Andrew C. Retzinger, Gregory S. Retzinger*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Microscopic poly(styrene-divinylbenzene) beads coated with a monomolecular film of fibrinogen agglutinate when stirred in the presence of thrombin, a consequence of interbead fibrin formation. Trypsin, by digesting bead-bound fibrin, dissociates bead aggregates at a rate proportional to the amount of enzyme activity. The agglutination of beads and the dissociation of bead aggregates can be monitored turbidimetrically using a platelet aggregometer or other photometric device equipped with a stirred cell. We have exploited the behavior of aggregates of fibrin-coated beads to develop a rapid, sensitive, and accurate method for measuring the activity of trypsin and its inhibition, in aqueous media, including serum. The new method yields serum antitrypsin activity levels that correlate well with immunological levels of α1- antitrypsin and, thus, may prove useful for assessing antitrypsin activity in clinical specimens.

Original languageEnglish (US)
Pages (from-to)114-121
Number of pages8
JournalAnalytical Biochemistry
Issue number1
StatePublished - Apr 1 2006


  • Enzyme activity
  • Fibrinolysis
  • Ovomucoid
  • Soybean trypsin inhibitor
  • Trypsin
  • Turbidimetry
  • α-Antitrypsin
  • α-Macroglobulin

ASJC Scopus subject areas

  • Molecular Biology
  • Biophysics
  • Biochemistry
  • Cell Biology


Dive into the research topics of 'A turbidimetric method for measuring the activity of trypsin and its inhibition'. Together they form a unique fingerprint.

Cite this