[Method of preparation and evaluation of antisera for the differential determination of secretory immunoglobulin A and free secretory component in biological fluids].

One of the pressing tasks in the study of local nonsusceptibility to infectious diseases and immunochemical analysis of the external secretion is recording of the level of various forms of the secretory IgA (SIgA) and of the secretory component (SC) in various biological fluids. Indication and measurment of the concentrations of the mentioned proteins encounter serious difficulties caused by heterogeneity of their molecular forms. It was shown that the antisera to the whole molecule of SIgA and SC are of no use. On the basis of a new method of purification of free SC and technology of preparation of monospecific antisera capable of separation of SIgA and free SC there were obtained diagnostic antisera for the quantitative recording and differentiation of various forms of IgA and SC in biological fluids. A reliable measurement of the SIgA and SC concentration in some external secretion was carried out with the aid of the mentioned preparations without any complicated chromatographic experiments.