Manual of basic techniques for a health laboratory - libdoc.who.int

9. Haematology 3054. Examine the colour of the film. It should appear mauve, neither too blue nor toopink.If the film is not satisfactory, return the slide either to the Field stain A or to theField stain B for a few more seconds, as needed.If the film is satisfactory, stand the slide in a draining rack to dry.How to remedy poor resultsDeposits of May–Grünwald stain or neutral waterDeposits caused by May–Grünwald stain or neutral water can be seen with thenaked eye in the liquid on the slide. Drain off the stain. Rinse the slide twice inmethanol. Dry and re-stain using fresh or filtered May–Grünwald stain.Deposits of Giemsa stainThese deposits are seen with the naked eye or under the microscope. Rinse withmethanol, but wash off immediately with neutral water. Dry the slide and repeatthe staining procedure from the beginning.Too much blue in the film (basophilic staining)Prepare a solution of 1% boric acid in 95% ethanol. Rinse the slide twice in thispreparation. Wash at once in neutral water. Dry and examine under the microscopewithout further treatment. Basophilic staining can usually be prevented by usingbuffered water at a more acid pH and, if necessary, altering the differentiation time.Poor staining may also be caused by impurities in the dyes — the use of the standardizedstain is recommended.9.10.4 Microscopic examinationUsing the ¥ 40 objective, examine the slides. The cells should appear as describedin Table 9.10.ErythrocytesIn certain diseases, especially anaemia, the erythrocytes may have an abnormalshape, size or colour. To check for abnormal erythrocytes, look at the cells justbefore the thin end of the film; this is where they are spread out, just touching oneanother, but not overlapping (Fig. 9.74). Do not look at either the thick end, wherethe cells are too closely packed (Fig. 9.75), or the thin end, where there are notenough cells (Fig. 9.76).The various types of abnormal erythrocytes are described below.Table 9.10 Appearance of blood cells in thin films stained withLeishman stainCell typeNeutrophilsEosinophilsBasophilsMonocytesLymphocyteslargesmallErythrocytesThrombocytesAppearanceCytoplasm stains faint pink and contains small mauve granulesCytoplasm stains faint pink and contains large red granulesCytoplasm contains numerous dark mauve-blue granulesCytoplasm stains grey-blueCytoplasm stains clear blueCytoplasm stains dark blueStain pink-redStain mauve-pink