ABSTRACT
In this study, samples of blood were collected from two hundred femalevolunteers aging between 18 and 23 years old. Two methods for MN groupingwere done, the first was "tube technique method", while the second was "tilemethod". Also, factors which may affect grouping by the two methods includingtime of reading of the reaction and the dilution of antiserum were tried. Theresults of grouping by using both tube and tile methods indicated that thehighest percentage [46%] was for MN blood group, followed by M blood group[34%], while N blood group showed the lowest one [20%]. Tube methodapplication revealed that M antigen was more potent than N antigen, so itsreaction was stronger. It was also found that best results can be obtainedwhen the antisera used are fresh, of a dilution ranging between 1/32 up to1/64 and the best time of reading of the reaction is after lapse of 3 hoursbut can be read with less strength after 2 hours. When the tile method wasapplied, strong +ve results for M antigen was found, and the best time ofreading was after 30 seconds from adding corresponding RBCs. The bestsuitable dilution for the reaction was 1/32 up to 1/64 for MN grouping