cells to be detected 1 3 see example 2 as well as anti human igg igm goat anti human igg goat anti human igm sigma i 3382 i 0759 serve as controls the positioning of the bonding elements of the indicator zone region u201c serum cross check antibody test u201d commence with erythrocyte ghosts of the specification blood group a1 in position x 2 5 mm y 10 mm the positioning of the erythrocyte ghosts of the specification blood group a2 b o is iterated at distances of x 2 mm y 1 5 mm the positioning of the erythrocyte ghosts of the mixture of the cells for detection 1 3 takes place in positions x 10 5 mm y 13 mm that of the human igg igm in position x 12 5 mm y 14 5 mm the erythrocyte ghosts are dispensed as 0 1 0 5 v v suspensions in 15 mm potassium phosphate buffer ph 7 5 10 v v methanol the anti human igg igm antibodies as 1 1 mixtures in a concentration of 50 u03bcg ml in 15 mm potassium phosphate buffer ph 7 5 10 v v methanol the positioning of the bonding elements of the indicator zone region u201c blood group determination u201d starts with the anti a antibody in position x 3 mm y 20 mm all other bonding elements of the indicator zone are dispensed iterated at distances of x 3 mm y 1 5 mm to the position of the anti a antibody the dilutions of the antibodies proceed in 50 mm potassium phosphate buffer ph 7 5 10 v v methanol as follows anti a antibody 1 3 anti b antibody 1 2 anti ab antibody 1 4 anti rbc.