Nirantara: A conservative approach to economical use of antisera in short-supply

Background and Objectives: Serological screening for rare antigens may hamper due to scarcity of the reagent antisera. The study aims to develop a conservative approach for scarcely available antisera to maximize outcome from minimum resource. Method: In the LISS tube test for screening the antigen using antiserum, the test supernatant (TS) was harvested after reading the results. The TS was reused in subsequent screening till it showed visible reactivity. The stage at which it ceases to react, the TS was concentrated by carbo-wax (polyethylene glycol) and reused for further screening. Results: Using 8-10 ml of antiserum to rare antigen In(a), we could screen as many as 6868 donors and found 200 donors with In(a+); with 5 ml of anti-Di(a), we could screen 2567 local donors from the Western India; none of them was Di(a+), but four of the 87 Tibetan migrants were positive for the antigen. We could use this approach even on antibody to high-frequency antigen with a slight modification, by adding to the TS the antibody eluted from the sensitized test cell for using in subsequent screening. Conclusion: The recycling of antibody can fruitfully be used several times to conserve the antiserum in short-supply.