What is Goriaev's camera? Rules for counting blood cells
Today, Goryaev's camera is one of the mostused devices in laboratory diagnostics. With its help, you can count the number of these or other blood cells. As you know, a blood test is extremely important for the diagnosis and treatment of almost every disease.
What is Goriaev's Camera?
Such a well-known and useful device waswas developed and proposed by the Russian physician NK Goryaev. Goryaev's chamber, in fact, is a specific slide glass with a microscopic grid applied to it.
What is this camera used for? First of all, it determines the number of blood cells, in particular leukocytes and erythrocytes. By the way, with its help you can determine the increase in the used microscope. The formula for this is as follows:
- Kg = (m2 - m1) / aN
In this case:
- Kg is the magnification of the microscope;
- m2 - position of the right boundary of the cell of the camera Goryaeva;
- m1 - position of the left border;
- a - the size of one cell, which is the standard and is 0.05 mm;
- N is the number of cells between the measured boundaries of the chamber.
The structure of the camera
Goryaev's camera is not that inno,as a slide (but much thicker than usual), divided by transverse grooves 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 cover glass - thus, a closed chamber with capillary spaces on the sides is formed in the center through which it is filled with liquid.
As for the grid, the camera GoryaevaIt 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 each. The length of each side of this small square is 0.05 mm.
Preparing to count the shaped elements
Undoubtedly, in this case the great importancehas a technique for conducting a laboratory study. Of course, all the surfaces of the Goriaev camera must be clean and dry. After that, the cover glass is rubbed so that you can see the characteristic rainbow rings. It is extremely important that there are no air bubbles in the chamber, as this can distort the results of the analysis.
Naturally, in order to calculate the quantityuniform elements, different reagents are used for each variety of blood cells. For example, 0.9% sodium chloride solution is used to count erythrocytes. In a test tube, mix 8 ml of salt solution and 0.02 ml of blood. So, the lab assistant dilutes the blood 400 times. Sometimes breeding can be great.
To calculate the number of white blood cells, mix 0.4 ml of acetic acid (take 3% or 5% solution) and 0.02 ml of blood.
After the components are mixed intube, using a special pipette, a small amount of mixture is collected and the chamber is carefully filled in for counting (as a rule, one or two drops will be enough).
How correctly to calculate the number of blood cells?
Counting red blood cells in Goryaev's cellis carried out in five large squares, which is eighty small. In order to avoid errors due to the uneven distribution of blood samples, the squares diagonally selected are selected. Special attention is paid to cells located at the edges - here they consider red blood cells on the left and upper walls, but do not take into account those that are located on the lower and right lines.
In order to determine the number of erythrocytes in a milliliter of blood, the number of cells in five large squares is multiplied by 20,000 (with a dilution of 400 times).
Gorokhov thinks that the leukocytes in the chamber are different. Here it is necessary to calculate the number of elements in at least a hundred large squares. The resulting amount is divided by 1600, then multiplied by 4000, and then by 20 (dilution rate).
