What are direct and indirect agglutination test?

Direct agglutination tests involve the clumping of particles, such as red blood cells or bacteria, directly by antibodies in a sample, indicating the presence of specific antigens. In contrast, indirect agglutination tests use coated particles, like latex beads, that bind to antibodies in the serum, resulting in visible clumping if the corresponding antigens are present. Both methods are widely used in clinical diagnostics to detect infections and autoimmune diseases.