Fixation of Tissues from Cases of Malaria

Abstract

Primary fixation is carried out in formalin (1:10 with water) for 3-6 hrs. (or in formol sublimate if the tissues be < 6 hrs. dead), followed by direct transfer to 5% aqueous HgCl2, in which fixation is continued for 5-20 days. The best formalin-free fixation method is to fix in aqueous 2.5% potassium bichromate and 5% HgCl2 for about 6 hours, then transfer directly to 5% HgCl2 aqueous solution for continuation of fixation. This does not interfere with the common methods of staining as the prolonged action of bichromate may do. This method gives the minimum of lysis of erythrocytes other than by the use of formalin, preserves the malarial pigment, and avoids the fallacy of formalin deposit.