Collection of mucosal secretion by synthetic discs for quantitation of secretory IgA and bacteria

A practical method for collection and processing of mucosal secretion was developed to facilitate quantitation of its contents of secretory IgA (sIgA) and bacteria. Small discs were punched out from a commercially available synthetic electrophoresis wick. The discs absorbed a constant volume of saliva (52.4 +/- 3.9 microliters), and antibodies and encapsulated bacteria (Neisseria meningitidis) could subsequently be completely eluted. Serum IgA, IgM and IgG antibody activity was preserved both in discs stored dry for 3 days at 22 degrees C and in discs stored at -22 degrees C for 2 months. The secretory IgA concentrations of multiple samples of nasal secretion collected from 1 person were stable, demonstrating the reproducibility of the disc collecting method.