A turbidimetric assay for quantitating functional fibrin(ogen) using polystyrene-divinylbenzene microparticles

Area of Science:

• Biochemistry
• Clinical Chemistry
• Assay Development

Background:

• Accurate quantification of fibrinogen is crucial for understanding hemostasis and diagnosing coagulation disorders.
• Existing fibrinogen assays have limitations in sensitivity or may not exclusively measure functional protein.

Purpose of the Study:

• To develop a highly sensitive assay for quantifying functional fibrinogen in plasma and aqueous solutions.
• To compare the performance of the new assay with standard clinical methods.

Main Methods:

• Development of a bead-based assay using microscopic latex particles coated with lecithin and fibrinogen.
• Measurement of fibrinogen concentration based on the rate of particle aggregation induced by thrombin.
• Validation against a standard clinical assay using plasma samples across a range of fibrinogen concentrations.

Main Results:

• The assay can quantify as little as 15 nM (approximately 5 microg/ml) of fibrinogen.
• Demonstrated high correlation (r2 = 0.9710) with a standard clinical assay over a range of 2.5 to 28.0 microM.
• Achieved analytical precision comparable to existing assays, with coefficients of variation of 12.7% at 30 nM and 7.1% at 15.0 microM.

Conclusions:

• The developed bead assay offers superior sensitivity, detecting 20-fold lower fibrinogen concentrations than routine clot-based methods.
• This method specifically measures functional fibrinogen, unlike immunological assays.
• The assay is suitable for researchers needing to measure low levels of functional fibrinogen.