Summary
A semi-automatized platelet counting procedure with the use of a Coulter Counter is
described. Its originality consists in providing an electronic method of counting
of the platelets after a differential centrifugation of the blood sample previously
diluted with a hypertonic NaCl solution (density 1.053) which is isopycnic to platelet
density. This procedure allows elimination of red and white cells without loss of
platelets in the supernatant. The final platelet number can be calculated without
further corrections.
The method is quick and does not require specially skilled technicians. A single technician
can perform 40 counts in one hour. The reproductibility of the method is excellent
and the coefficient of variation 2,4 %.
The accuracy and feasibility of the method is also sustained by two years’ experience
in an haematological routine laboratory.
