While red cell counts can be performed by manual techniques, these are time-consuming and inaccurate.
New methodology allows the counting of erythrocytes by flow cytometry.
This is the technique used by our new hematology analyzer, the Advia. The sample is first diluted, then counting is perf ormed by drawing the cells through an aperture of the instrument. Each cell causes a change in electrical resistance as it passes the aperture, and this pulse is detected and amplified by the instrument. This is the standard instrument used for cell counts in body fluids, other than blood, e.g. joint fluids, peritoneal fluids, because these fluids cannot be analyzed through the Advia. Flow cytometry counters With the Advia, red cells are sphered in a diluent and then passed through a laser.