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

306 Manual of basic techniques for a health laboratoryFig. 9.74 Examining blood films for abnormal erythrocytes: where to lookFig. 9.75 Examining blood films for abnormal erythrocytes: cells too closely packedFig. 9.76 Examining blood films for abnormal erythrocytes: not enough cellsNormal erythrocytes (Fig. 9.77)Size: 6–8mm.Shape: round, discoid, occasionally slightly irregular.Cytoplasm: periphery deep pink, centre pale pink or colourless.Target cells (Fig. 9.78)Size: 6–8mm.Shape: round or slightly irregular.Cytoplasm: centre and periphery stain well, but between them there is a colourlessring.Seen in thalassaemias, vitamin B 6deficiency, haemoglobinopathy, liver diseases,sickle-cell anaemia and iron-deficiency anaemia.