FIG. 1.

Detection of SP-D in human tear fluid by ELISA. Human tear fluid (triangles) and recombinant human SP-D (circles) were titrated on mannan-coated wells in the presence of 5 mM Ca²⁺ (solid symbols) or 5 mM EDTA (open symbols). The dilution series commenced at 1 μg of recombinant human SP-D/ml and at a 1:10 dilution of tear fluid. The assay was developed with rabbit anti-human SP-D antibody and HRPO-conjugated swine anti-rabbit Ig, as described in Materials and Methods. Human tear fluid was calculated to contain between 2 to 5 μg of SP-D/ml (see text).