Context: The antiglobulin test is an important test in the detection of immunoglobulin or complement bound on the surface of red blood cells (RBC) and serum antibodies. It is possible that anticoagulants used for collection of blood samples may affect the end result of this test. Aim: To study the variation in degree of agglutination between the antiglobulin test performed on plain blood and anticoagulated blood. Settings and Design: Antiglobulin Test was performed on blood samples collected from umbilical cord of 100 new-born babies during delivery in plain vials and vials with anti-coagulant like ethylenediaminetetraacetic acid (EDTA) and citrate. Methods and Materials: 6 ml of blood samples were collected from umbilical cord immediately after delivery and 2 ml each transferred into: EDTA, Citrate and Plain vials. The sample thus collected was used for performing the direct antiglobulin test. 10% red cell suspension was sensitized with Anti D IgG (as supplied by Tulip diagnostics) at different dilutions of 1/10, 1/20, 1/30 and 1/40. The washed saline suspension of RBC’s is treated with Anti- human globulin serum and agglutination is observed under a microscope at 5X bjective. The picture is taken of microscopic field using MIPS (micro image processing system) and saved Statistical Analysis used: Friedman test and Wilcoxon signed-rank test. Results: The degree of agglutination at various dilutions obtained by using plain blood samples was found to be higher than that obtained by using anticoagulated blood. The citrated blood samples gave intermediate agglutination results between blood samples collected in plain and EDTA vials.

Keywords: Antiglobulin Test; Agglutination; EDTA; Citrate.