LAB 18 - Blood Cells of Birds and Fish
|All avian and reptile blood cells are nucleated, therefore,
leukocyte counts must be done manually with a hemacytometer. The purpose of this lab was
to accurately determine the red blood cell count of one rainbow trout and one goose with a
hemacytometer. A Hemacytometer is a specialized microscope slide with two grids, of known
dimensions, etched on the central surface.
Red Blood Cell Count
Dr. Allen made 200 fold dilutions of the blood from each fish and the goose for us. This was done to enable us to differentiate the various cell types. We first placed a cover slip over the grid on the hemocytomerer slide. A small sample of diluted blood was then carefully applied to the edge of the cover slip using a micropipeter. The blood should flow under the cover slip and over the grid by capillary action. However, you have to be careful not to apply too much. You dont want any of the dilute blood sample to overflow down into the moat. Using the 10X objective on the microscope, we then counted the total number of red blood cells that are in the five numbered squares. The red blood cells that fell on the line of the grid were only counted if they were on top of, or to the right side of the line of the square.