Counting cells with a Hemocytometer

The basic idea

Cell count can be done directly from the vial than likely, you do not keep an order of magnitude of the amount of cells that you might be a display. You also do not recognize a particular area that you can select each time the same way , and you can not tell if the area you expected is significant or not . What I'm trying to explain is : there is certainly a standard way . It's called hemocytometer. Hemo , blood Cyto for the cell; meter to measure . So in total : measurement of blood cells.

Basically, when the hemocytometer was invented, the guy (Louis- Charles Malassez ) attempted to count blood cells. But ultimately , the goal is always to count cells that are suspended , so all cells could actually be counted.

principle

A hemocytometer sculpted cabin is a square inside a piece of glass which has a certain depth. The main square has several other small squares contained .

Each of the 9 large square included in the square region is identical . In addition, each of the sixteen squares within each of the four cases is the same surface angles . What this means is basically that if you count the cells in the boxes that have exactly the same size, you can take the average of the counts you get, that will surely be illustrative of the cellular concentration of your culture. You should also consider that if your cell concentration is high enough, then you go and count the cells in the square minor rather than major .

the procedure

As we said earlier, it is important to have a sample of the suspension culture cells to perform a number of cells. If you want to determine the viability and then you want to add a viability dye (1:1 dilution usually works best ) . Ultimately , it will be your sample count . Further diluted if it is very concentrated. Bring your hemocytometer , set a glass slide above (make sure it does not move , if it puts little ethanol / moisture to stick to the surface ) and insert mu.l 10-20 your counting solution ( dilute if necessary , use colorants sustainability to make the difference between living and dead cells). Meticulously , insert it in between the blade and reduces the hemocytometer ( it will come by capillarity ) space. When the space is filled , you are done with one side. Repeat with the other large square of the hemocytometer if desired (better precision). At the moment you 're ready to go under the microscope. Place hemocytom eter under the lens , so that you see the first small street of the great high place in the middle of your field of vision.

Starts from your cells. You must determine which two edges of your site you are going to throw . Because you can count only once cells and some cells will probably be half - half starting place you intend , it is common to choose which 2 to count and those who undo . However keep them constantly throughout your account.

Once you get the number of cells in the original box, you must go to the second and that as well. Remember: If you examined the cells on the top and sides of the right, but not the ones on the bottom and left edges of the 1st place , then do exactly the same with the one that follows . Keep counting squares until you have enough for your cell number statistically significant ( in summary, if you have a different number of cells, the difference between the two counts is not very large) . It is strongly recommended that you have at least 100 cells , which should give you an idea of just how small squares , you need to count . Maintain the symmetric counting (that is to say , if you intend to have 3 small squares in the big square , count the top right, middle and bottom left squares into a large square). Also, do not forget to write your account whenever you end up with a square and reset your check meter to zero or count all the quillet s and write down the full amount and then also write how many places that you expected, with the intention to take the average . Most greatest of all accounts is that it is not necessary to reset your counter to 0 every time, but the disadvantage of this approach is that if you are unsure of any of the Heads of charge in a square, there is no going back , you will start from 1st place .

calculations

Excellent . You have your account. Now take the average of cells for each square ( total of all cells in each square you counted , divided by the total number of places you counted ) , multiply by the dilution factor ( in case you n ' do not dilute the sample , multiply by 1) and divide by the volume ( in mL ) of a small square .

The volume of a small spot is specific to the hemocytometer . It is calculated by multiplying the width by the height (which are exactly the same - usually 1mm each), the depth (usually 0.1 mm) with a small square . In the most common case , it would be 10000 .

With the density of the measured cells, you will calculate how media you need so that you can reach the cell concentration suggested by the manufacturer.

If you have already suspended the cells in fresh medium , subtract the final volume to add.

There you go!

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