Effects of sample-diluent interactions on surface tension and pressures in continuous flow manifolds

When a plasma sample is aspirated into a continuous flow analyser the internal pressure of the manifold increases. The pressure change is the result of insufficient detergent present to bind all the protein in the sample, and is a potential source of inaccuracy and imprecision in the assay. It is recommended that Brij 35 be used at a concentration 10 times above the binding capacity of the albumin in the sample, to minimise changes in pressure between samples.