STATISTICAL EVALUATION OF AN IMPROVED QUANTITATIVE IMMUNOFLUORESCENCE METHOD OF MEASURING SERUM ANTIBODY-LEVELS DIRECTED AGAINST INTESTINAL BACTERIA

The accuracy of an improved quantitative immunofluorescence method to measure the antibody binding capacity of intestinal bacteria was assessed. The improvements comprise: calibration on a non-fading fluorescence standard (uranyl glass), prolonged camera exposure time (over 4 s) and shading correction of the digitized image. This method can measure levels of IgG, IgM and IgA with variation coefficients of 6.1%, 6.4% and 9.8%, respectively. With this accuracy biological alterations in the antibody binding capacity of intestinal bacteria can be monitored at a statistically significant level.