Manual cell counts. An. Lab. Proc. 1 hematology book pg 19

What is the oldest and most time consuming method of determining blood cell counts?

What is required for microscope counting of red and white cells

The hemocytometer is calibrated to hold a known volume of fluid between the cover slip and a grid etched on the slide

The hemocytometer is calibrated to hold an unknown volume of fluid between the cover slip and a grid etched on the slide

Microscopic counting (with hemocytometer) can also be used for counting cells in other body fluids and effusions

Microscopic counting (with hemocytometer) cannot be used for counting cells in other body fluids and effusions

Different dilutions for red and white cell counts are necessary

Different dilutions for red and white cell counts are not necessary

For white cell counts, erythrocytes are lysed

For white cell counts, erythrocytes are diluted with methanol

Which of the following provides a convenient and reproducible system of pre-measured diluents according to the Hematology book in page 9

Red cells can be counted using a hemocytometer, but the margin of error is high even among skilled medical technologists

Red cells can be counted using a hemocytometer, since the margin of error is low even among less skilled medical technologists

Red cell counts themselves offer little additional information over the hematocrit. They are needed to calculate of red cell indices, but manual counts are generally too variable to yield reliable information

Reticulocyte count is performed by counting at least 1,000 erythrocytes on a smear made with supravital (new methylene blue) stained blood.

Red cell counts themselves offer a lot of additional information over the hematocrit. Therefore they are needed to calculate of red cell indices, and manual counts are generally expected to yield reliable information

Reticulocyte count is performed by counting at least 100 erythrocytes on a smear made with supravital (old methylene blue) stained blood.

The absolute reticulocyte count is determined by multiplying the red cell count times the percent of reticulocytes.

The absolute reticulocyte count is determined by summing the red cell count by the percent of reticulocytes.

Differential white cell count – The stained smear should be examined with the oil immersion lens.

Differential white cell count – 100-200 white cells are characterized by type. The larger the number counted, the smaller the margin of error

Differential white cell count – The stained smear should be examined with the high dry objective lens

Differential white cell count – 100-200 white cells are characterized by type. The smaller the number counted, the smaller the margin of error

Differential white cell count Avoid areas where cells are overlapping or distorted. Use a consistent method to scan the slide to ensure random sampling and avoid counting the same area twice

Differential white cell count Avoid areas where cells are overlapping or distorted. Use a consistent method to scan the slide to ensure random sampling and DO NOT avoid counting the same area twice

Differential white cell count -The percent of each cell type is multiplied by the total white cell count to determine the absolute number of each leukocyte/µl

Differential white cell count -The percent of each cell type is divided by the total white cell count to determine the absolute number of each leukocyte/µl

Differential white cell count -Absolute numbers (not %) should always be used in evaluating the hemogram.

Differential white cell count -Percentage (not absolute number) should always be used in evaluating the hemogram.