Interpretation and Validation of Maximum Absorbance Data Obtained from Turbidimetry Analysis of Plasma Clots.
Turbidimetry is used to characterize fibrin clot properties. In purified systems, maximum absorbance (MA) directly relates to fibrin fiber cross-sectional area. However, in plasma samples there are discrepancies in the relationships between MA and fibrinogen concentration, fiber diameter, other clot properties, and cardiovascular disease outcomes, which complicate data interpretation. This study aims to advance understanding of MA of plasma clots through testing how well it relates to fundamental dependence on fibrinogen concentration and fiber diameter as predicted by light scattering theory, other clot properties and lifestyle, and biochemical variables. Plasma samples from 30 apparently healthy individuals with a fibrinogen concentration from 2.4 to 6.4 g/L were included. We performed turbidimetry, permeability, scanning electron microscopy, and rheometry on in vitro formed plasma clots. MA correlated more strongly with fibrinogen concentration (r = 0.65; p