Today Goryaevâs camera is one of the most used devices in laboratory diagnostics. With its help, you can calculate the number of certain blood cells. As you know, a blood test is extremely important for the diagnosis and treatment of almost every disease.
What is Goryaevâs Camera?
Such a well-known and useful device was developed and proposed by the Russian doctor N.K. Goryaev. Goryaevâs camera, in fact, is a specific glass slide with a microscopic grid deposited on it.
What is this camera used for? First of all, it helps to determine the number of blood cells, in particular leukocytes and red blood cells. By the way, with its help, you can determine the increase in the used microscope. The formula for this is as follows:
In this case:
- Kg is an increase in the microscope;
- m2 is the position of the right border of the cell of the Goryaev chamber;
- m1 is the position of the left border;
- a - the size of one cell, which is standard and is 0.05 mm;
- N is the number of cells between the measured boundaries of the chamber.
Camera structure
Goryaevâs camera is nothing more than a glass slide (but much thicker than usual), divided by transverse furrows into three parts. The middle part of the glass contains a special grid for counting. The extreme parts of the chamber serve for rubbing the coverslip - thus, in the center, a closed chamber is created with capillary spaces on the sides through which it is filled with liquid.
As for the grid, the Goryaevâs camera is divided into 225 large squares of equal sizes - they are located in fifteen rows. 25 large squares are additionally divided into smaller ones, 16 in each. The length of each side of this small square is 0.05 mm.
Preparation for counting shaped elements
Of course, in this case, the laboratory research technique is of great importance. Of course, all surfaces of Goryaevâs cell should be clean and dry. After this, the coverslip is rubbed so that you can see the characteristic rainbow rings. It is imperative that there are no air bubbles in the chamber, as this can distort the results of the analysis.
Naturally, in order to calculate the number of shaped elements, different reagents are used for each type of blood cell. For example, a 0.9% sodium chloride solution is used to count red blood cells. In a test tube you need to mix 8 ml of salt solution and 0.02 ml of blood. So, the laboratory assistant dilutes the blood 400 times. Sometimes breeding can be great.
In order to calculate the number of leukocytes, you need to mix 0.4 ml of acetic acid (take 3% or 5% solution) and 0.02 ml of blood.
After the components are mixed in a test tube, using a special pipette, collect a small amount of the mixture and carefully fill the chamber for counting (as a rule, one or two drops will be enough).
How to calculate the number of blood cells?
The red blood cell count in Goryaevâs cell is carried out in five large squares, which is eighty small. In order to avoid errors due to the uneven distribution of blood samples, diagonal squares are chosen. Special attention is paid to cells located at the edges - here the red blood cells are counted on the left and upper walls, but those that are located on the lower and right lines are not taken into account.
In order to determine the number of red blood cells in a milliliter of blood, the number of cells in five large squares is multiplied by 20,000 (when diluted 400 times).
White blood cells in Goryaevâs cell are considered differently. Here you need to calculate the number of elements in at least a hundred large squares. The resulting amount is divided by 1600, after which it is multiplied by 4000, and then by 20 (the degree of dilution).