Rh and Other Blood Groups

Laboratory Procedures in Blood GroupingIt must be emphasized at the outset that blood-grouping procedures are at present in an imperfect state of development. The tests are still dependent in all routine work on the phenomenon of red-cell agglutination. Although this is an extremely sensitive method, as many biologic tests are, it is somewhat unpredictable, being dependent on certain physicochemical and biologic factors. Red cells must be well preserved in serum or in the clot and relatively fresh (one to three days old is best although adequate preservation for several weeks is possible with respect to some of the . . .