A direct, automated, immuno-turbidimetric assay of free protein S antigen in plasma.

Abstract

A new, fully automated, one-step, immuno-turbidimetric assay of free protein S (fPS) in plasma (STA Liatest Free Protein S; Diagnostica Stago, Asnières, France) has been developed for STA analysers. This technique combines the advantages of a direct assay of fPS using two monoclonal antibodies, which specifically recognize fPS but not protein S (PS)-C4b-binding protein complexes, and the advantages of automation. The assay has good analytical performances, with intra- and inter-assay variation coefficients below 5% for normal values, and slightly higher for abnormal values. In a comparison study with a one-step enzyme-linked immunosorbent assay for fPS (Asserachrom Free Protein S; Diagnostica Stago), a correlation coefficient of 0.93 with a regression line close to 1 was found between the two techniques (n = 166 normal or PS-deficient plasma samples collected from healthy subjects and individuals with a personal or family history of thrombosis). This new technique is specific, reproducible, easy to perform, and provides a useful tool in the diagnosis of PS deficiency.

• Authors: C Deffert, F Esteve, M Grimaux, M Gouault-Heilmann
• Journal: Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis (Blood Coagul Fibrinolysis) Vol. 12 Issue 2 Pg. 137-41 (Mar 2001) ISSN: 0957-5235 [Print] England
• PMID: 11302476 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Antibodies, Monoclonal
• Protein S

Topics

• Adolescent
• Adult
• Aged
• Antibodies, Monoclonal
• Autoanalysis
• Child
• Child, Preschool
• Enzyme-Linked Immunosorbent Assay
• Female
• Humans
• Immunoassay
• Male
• Middle Aged
• Nephelometry and Turbidimetry
• Protein S (analysis)
• Protein S Deficiency (blood, diagnosis)
• Quality Control
• Reference Values
• Reproducibility of Results
• Sensitivity and Specificity
• Sex Characteristics