Visual Red Cell Count


Counting red cell with hemocytometer

On these post, we are going to study visual red cell count. In brief explanations; visual red cell count is a hematological procedure for counting the number of red cell present in a given sample, and the cell count taken to represent the total cell count of the red cell of the patients which the sample is collected from.

Practical procedure

To count red cell of a particular sample, it required dilution. Formol citrate is the most available diluents used now for visual cell count.

Preparation of formol cirrate

1. 10ml of formalin (40% of formaldehyde.

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2. 1 litre of 31.3g/l trisodium citrate solution

The reagent should be mixed together, then filter and then store in a clean glass containers until the need arise.

Test procedure

Measure 2micro litre of a whole collected into EDTA( ethylene Diamine tetracetic acid )containers, is washed by taken into a shellbacks pipette or positive displacement pipettes.

The blood is diluted with 4.0ml of diluents to give a final dilution of 1 in 201 dilution.


Now is time to load your hemocytometer with a diluted sample, after loading the hemocytometer, keep the hemocytometer to settle, after that mount your hemocytometer on your microscopic state and count the red cell found on 5 of the 0.04mm² area of the hemocytometer. Point to note is that if you have less than 500 number of red cell count within these 5 area, then it is advisable to count the total central area of 1mm². By these count, it will reduce the inherent statistical error, and then rise the confidence on the final result.

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The final should be express as the number of cell per litre.

On calculating the number of red cell count the following formula should be use

N x DF x 106

Red cell count = —————————

A x D

N = the number of cell count

DF = dilution factor(201), 106

A = area chamber counted(0.2mm²)

D = depth of the chamber (0.1mm)

We have come to an end of our post. If you have any question or comment, please drop it on our comment section below. Thanks for reading.


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What about white blood cells?