NONINSTRUMENTAL IMMUNOASSAY BASED ON COLO RED POLYACROLEIN LATEX - APPLICATION TO GROUP-SPECIFIC POLYSACCHARIDE OF STREPTOCOCCUS-PYOGENES

Non-instrumental immunoassays based on immunofiltration and microtiter particle agglutination (MPA) techniques have been developed using col oured polyacrolein latex. These methods have been applied to the quant ification of the group-specific polysaccharide (PS) of S. pyogenes (gr oup A streptococcus) and compared with standard ELISA tests. The most efficient method was MPA; as little as 0.05 ng A-PS/ml could be detect ed in 1.5 h. In comparison with ELISA test, the sensitivity of MPA was 10 times higher and the procedure was much simplier. The sensitivity of immunofiltration assay using both enzyme and latex conjugates was s hown to be the same (50 ng/ml A-PS) and the duration of the assay 3-5 min. No cross-reactions of latex conjugates with non A streptococcus c ell lysates have been observed. The developed methods are rapid, robus t, easy to perform, don't need any sophisticated equipment and special ly trained staff.