DETECTION OF MENINGITIS ANTIGENS IN BUFFER AND BODY-FLUIDS BY ULTRASOUND-ENHANCED PARTICLE AGGLUTINATION

The standard test card agglutination of antibody-coated latex by Neiss eria meningitidis, Streptococcus group B, Haemophilus influenzae type b and Streptococcus pneumoniae antigens has been compared with a techn ique involving local concentration of the coated latex in an ultrasoni c standing wave. The detection of positive control antigen was enhance d, compared with the test-card procedure, over a 16 to 64 fold range o n exposure to ultrasound. Sample filtration eliminated non-specific ag glutination on ultrasonic exposure of latex in control serum, urine or concentrated urine. Tests of meningitis patient body fluids showed in creased detection of antigen with ultrasound for CSF (11/14 > 7/14) se rum (8/13 > 3/13) and concentrated urine (8/17 > 2/17) compared to tes t card assays. The ultrasound detection of antigen in serum or concent rated urine was comparable to that achieved with CSF on test cards. Se rum dilution experiments showed that ultrasound could detect antigen i n serum over a 1000 fold concentration range. (C) 1997 Elsevier Scienc e B.V.