FIG. 1.

SAP prevents the serum-induced dequenching of FITC-LPS. (A) Normal serum (2%) or SAP-depleted (SAP⁻) serum (2%), obtained from the same donor, replenished with increasing amounts of SAP was incubated with FITC-LPS (0.5 μg/ml) at 37°C under continuous agitation. (B) The contribution of SAP in the dequenching of FITC-LPS was also tested by preincubating normal serum with rabbit anti-human SAP antibodies (30 μg/ml) before the addition of FITC-LPS. Fluorescence, as a measure of serum-induced dequenching of FITC-LPS, was measured at set time periods on a fluorometer. Data represent the mean fluorescence ± SEM of three separate experiments performed in triplicate.