Antibody affinity is a quantitative measure of binding strength whereas antibody avidity incorporates the affinity of multiple antigen-binding sites.
Radioimmunoassays are high sensitivity in vitro assay techniques to measure concentrations of antigens using specific antibodies.
When microbial toxins and specific antibodies combine and the active portion of the toxins are blocked, neutralization occurs.
Indirect fluorescent antibody test (IFA) is a semi-quantitative, sensitive, and rapid test to detect specific antibodies or antigens.
Detection of specific antigens present in the sample (blood, urine, or CSF) using specific antibodies is the mainstay for the rapid diagnosis of infections.
Detection of IgM, or Ab titre more than local cut-off titre or four-fold rise in Ab titre between acute and convalescent period is diagnostic.
Pneumococcal urinary antigen testing is a rapid assay that detects Streptococcus pneumoniae antigen (C-polysaccharide) in the urine of patients.
