title: A photometric assay for blood coagulation factor XIII.
abstract: An assay for a direct photometric determination of F XIII in untreated and undiluted plasma was developed. In a one-step procedure F XIII is activated by thrombin and Ca2+ and cross-links glycine-ethylester to a specific glutamine containing peptide substrate. The released ammonia is incorporated into alpha-ketoglutarate by glutamate dehydrogenase, and the NADH consumption of this reaction is measured photometrically at 340 nm. NADH-consumption is directly proportional to the F XIII activity. Fibrin polymerization and the corresponding turbidity is avoided by the use of a fibrin aggregation inhibitor. The procedure is rapid and simple and enables to measure within the range of 0 to 150% F XIII. It can be performed with automated analyzers as well as with common photometric equipment. The normal range of F XIII activity in 167 healthy donors was determined to be 70 to 140%.
authors.affiliation: Research Department for Blood Coagulation, Behring Werke, Marburg, FRG.
authors.forename: K
authors.initials: K
authors.lastname: Fickenscher
authors.forename: A
authors.initials: A
authors.lastname: Aab
authors.forename: W
authors.initials: W
authors.lastname: Stüber
mesh_terms: D000595:Amino Acid Sequence; D002138:Calibration; D005176:Factor XIII / Q000032:analysis*; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D010783:Photometry; D015203:Reproducibility of Results
chemical_list: D005176:Factor XIII