This study describes the development of a method for the recognition and definition of leucocyte group Four. The method can also be applied to the detection of other leucocyte groups. Essential... Show moreThis study describes the development of a method for the recognition and definition of leucocyte group Four. The method can also be applied to the detection of other leucocyte groups. Essential factors in the method were: a) the use of leucocyte agglutinins formed during pregnancy; b) an insight into the shortcomings of the agglutination test; c) the use of statistical methods to overcome these shortcomings; and d) the use of a panel consisting of the leucocytes of the women who had formed the agglutinins, and of those of their husbands. This study describes the development of a method for the recognition and definition of leucocyte group Four. The method can also be applied to the detection of other leucocyte groups. Essential factors in the method were: a) the use of leucocyte agglutinins formed during pregnancy; b) an insight into the shortcomings of the agglutination test; c) the use of statistical methods to overcome these shortcomings; and d) the use of a panel consisting of the leucocytes of the women who had formed the agglutinins, and of those of their husbands. Show less