The Effects of Size of Sampling Area and Dilution on Leucocyte Counts in a Hemocytometer
Creators:Ramsey, James M.
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Citation:The Ohio Journal of Science. v69 n2 (March, 1969), 101-104
With nearly 5000 areas examined, the comparison of a Poisson distribution to the distribution of leucocytes in a hemocytometer chamber at both 1:100 and 1:25 dilutions indicated a poor fit (P= <0.0001), a non-random distribution. In a series of leucocyte determinations from a young, male university student comparing 28 counts from 18 mm2 (both chambers) with 28 from 9 mm2, and 28 from 4 mm2 (the usual standard), the mean from the 18 mm2 counts was not significantly different from that of the 9 mm2 counts. However, both the means of the 18 mm2 counts and the 9 mm2 counts were significantly different from that of the 4 mm2 counts (P = 0.02 and 0.035 respectively). Forty-two counts at 1:100 dilution had a mean not significantly different from that of 42 counts at 1:20 dilution (P = 0.06). It appears that the counts from the 18 mm2 area at 1:100 dilution are the most reliable and are therefore recommended for critical research determinations. Fourteen such counts had the most restricted range and the lowest standard deviation of any of the six combinations.
Author Institution: The University of Dayton, Dayton, Ohio
Rights:Reproduction of articles for non-commercial educational or research use granted without request if credit to The Ohio State University and The Ohio Academy of Science is given.
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