Abstract: Objective To compare the effectiveness of the anti-human globulin microcolumn agglutination method and the traditional saline medium test tube method in detecting unexpected antibodies in red blood cells, and to explore the value of using both methods in parallel for antibody screening. Methods We retrospectively investigated 2 518 samples from the Shanghai Blood Center, which underwent unexpected antibody screening between January 2014 and December 2024. Our study focused on the detection of eight types of antibodies (anti-M, anti-Le^a, anti-Mur, anti-Le^b, anti-P₁, anti-Di^a, anti-Fy^b, and anti-S) using the saline test tube method. Cases where both the saline medium test tube and the anti-human globulin microcolumn agglutination methods were used in parallel were selected for comparison. Data were analyzed using SPSS 22.0, and differences were assessed with McNemar's test (paired chi-square test). Results The detection rates for the antibodies were as follows: anti-M (96% by the saline method vs. 62% by the microcolumn method), anti-Le^a (60% vs. 97% ), anti-Mur (60% vs. 97%), anti-Le^b (84% vs. 70% ), anti-P₁ (89% vs. 40%), anti-Di^a (10% vs. 99% ), anti-Fy^b (4% vs. 88% ), and anti-S (16% vs. 99% ). Conclusion The anti-human globulin microcolumn agglutination method outperforms the traditional saline medium test tube method in detecting most unexpected antibodies, offering advantages in automation and ease of use. However, the saline test tube method shows higher sensitivity for certain antibodies (e.g., anti-M and anti-P₁), though the clinical significance of these antibodies remains unclear and warrants further investigation.

Key words: Microcolumn gel method, Saline Tube Method, Irregular Antibodies