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

9. Haematology 283Fig. 9.34 Centrifuged capillary blood sampleE: erythrocytes; L: leukocytes; P: plasma.Fig. 9.35 Measuring the erythrocyte volume fraction using the micro scaleerythrocytes is still on the zero line; also check (by means of the heavy verticallines) that the tube is vertical.5. The line that passes through the top of the column of erythrocytes gives theerythrocyte volume fraction (0.4 in Fig. 9.35). The light intermediate lines representintervals of 0.05; if the top of the column of erythrocytes is not on a line,but between a heavy line and a light line, its position can be estimated to thenearest 0.01.Note: If your laboratory has not yet changed to SI units and is still using the traditionalsystem, the same chart can be used. Simply read the numbers as percentagesinstead of fractions. For example, instead of “erythrocyte volume fraction, 0.4”report the result as “packed cell volume, 40%”.