Appraisal of Instrument for Counting Erythrocytes by Scatter Photometry: With an Adaptation for Hemoglobin Determination

Abstract

An evaluation of the physical properties of a new instrument developed in Germany by Loeschcke and Wever for the purpose of counting erythrocytes is presented. The instrument employs an annular photocell which permits the increase in intensity of scattered light with increase in erythrocyte size to be partially compensated by the coincident shrinkage of the scatter pattern. The instrumental count was found substantially independent of cell size over the limited range of 7.5-8.5 [mu]. Compensation did extend, but to a lesser degree, into cell sizes outside of this range. To date leukocyte counting has been unsatisfactory. The hemoglobin detn. by this instrument appears on limited study to compare favorably with standard photocolorimetric procedures.