STAINING OF BLOOD FILMS (Differential Counting)

STAINING OF BLOOD FILMS (Differential Counting)

PREPARATION OF FILM FOR STAINING

                     Take few perfectly clean grease free slides. Clean the finger or ear lobe and prick as described for the collection of capillary blood. Touch the end of a slide to a large drop of blood and then spread entirely across the end of the spreader slide (the spreader must be held at an angle of about 45 degree), with a quick movement push the spreader towards the other end of underside. The blood film should not be too thin or too thick. Allow the blood to dry.

Leishman’s method:

         A romanowsky type stain designed to differentiate leucocytes

                     Leishman’s stain powder        -           0.15g

                     Methyl alcohol, acetone free   -           100ml

                     Take 0.15g of Leishman’s stain powder in a glass mortar, ad few ml of methyl alcohol grind to dissolve the stain completely. Transfer the stain to 100ml measuring cylinder. Add few ml of   methyl  alcohol into the mortar and grind. Repeat   the  same till the

 Leishman’s stain powder completely dissolves. Make the volume upto 100ml with methyl                alcohol. Pour the stain in a clean dry bottle and close it well. The stain is ready to be used for 3-4 weeks. The blood films are placed in a level position. The dry blood film is covered with the stain which should be evenly distributed over the entire slide. At the end of the min double the quantity of buffer solution or distilled water is carefully added and mixed with stain by means of clean pipette. The film is allowed to stain for seven to eight min and the excess stain is removed by washing with the distilled water. The water is then washed off with fresh distilled water. Dry the film in air when the film is dried, examine microscopically.