The lack of reliable, standardized testing protocols for antisperm antibodies has contributed to uncertainty among fertility specialists concerning the magnitude of such immunologic phenomena in human reproductive failure. The large size of the agglutinate limits the ability of the assay to determine the region of the sperm to which the antibody is bound, and restricts its utility in evaluating the percentage of antibody-bound sperm. Exposure of internal antigens may lead to false positive results because these antigens may cross-react with antibodies to bacterial antigens that are not related to infertility. The immunobead test (IBT) uses polyacrylamide beads coated with antibodies against human immunoglobulins (Igs) to bind to antibody-coated sperm. Sperm mixed agglutination reaction (SPMAR) is more sensitive in identifying sperm with antibodies of the IgG class on their surface. Antisperm antibodies could interfere with ion pumps or channels that regulate intracellular ion concentrations.