Can cells be cultured without buffer solution?

In cell culture, the respiration of cells will produce a lot of CO2, and the combination of water will reduce the pH of the growth environment of the cells, (acidification), which is not conducive to the culture of cells, in order to ensure that the culture environment of cells is in a reasonable acid-base balance environment, it is necessary to add buffer to the culture medium to neutralize part of the CO2 to ensure the pH balance of the culture.

1. PBS (phosphate-buffered saline) phosphate buffer.

Solution: sodium phosphate dibasic solution, sodium hydrogen phosphate dibasic (anhydrous), sodium chloride plus deionized water or double distilled water to 1000ml

Solution: sodium phosphate monobasic solution, sodium dihydrogen phosphate (anhydrous), sodium chloride plus deionized water or double distilled water to 1000ml

Liquor A and B should be stored at 4, prepared to the required pH concentration according to the ratio shown in Table 3-2 when used, and stored at room temperature after autoclaving.

Purpose: The buffer helps to maintain a constant pH level. The osmotic pressure and ion concentration of the solution are usually similar to the pH of the human body (isotonic).

2. HEPES liquid.

Biological buffers, chemically stable and within the range, have a stronger buffering capacity than NAHCo3 buffers.

The full name of HEPES in English is: 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid; n-2-hydroxyethylpiperazine-n'-2-ethanesulfonic acid; 2-[4-(2-hydroxyethyl)-1-piperazine]ethanesulfonic acid

Full name in Chinese: 4-hydroxyethylpiperazine ethanesulfonic acid; N-(2-hydroxyethyl)piperazine-N'-2-ethanesulfonic acid.

Molecular formula: C8H18N2O4S

Molecular weight: Uses: No toxic effect on cells. It is a hydrogen ion buffer that controls a constant pH range for a long period of time. The final concentration is 10-50 mmol L, and the buffer capacity can be achieved by containing 20 mmol Lhepes in the general culture medium.

10 mmol l is commonly used for cell culture.

The preparation method of 10 mmol L HEPES buffer is as follows: accurately weigh HEPES and add fresh tri-distilled water to set the volume to 1L. Filter and sterilize, and store after aliquoting4.

3. NaHCO3 buffer.

It is a part of the conventional buffer system, but it is unstable and susceptible to the pH value of the CO2 content in the air, which affects the buffering effect.

Phosphate buffers and NaHCO3 buffers are commonly used because they are easier to configure and less expensive.

No, cell metabolism does not change the pH of the medium, and the cells themselves are sensitive to pH.

It only has a buffering effect, not a buffer, the buffer is a solution system composed of strong alkali weak salt-weak acid or strong acid and weak alkali salt-weak alkali, borax is sodium tetraborate, which belongs to a strong alkali and weak salt, and only has a buffering effect on acid, and a buffering effect on alkali is very weak. To calculate the pH value, you need to know the ionization constant ka of tetraboronic acid, let it be a dibasic acid, then the pH value of the borax solution is 7+, and C is the concentration of the solution, which is suitable for solutions that are not particularly diluted.

For whether to use serum when the virus infects cells, it depends on whether the virus you are inoculating is sensitive to serum, and if it is sensitive, you must dilute the virus with serum-free medium, that is, maintenance solution, such as influenza virus; If the virus is not sensitive to serum, a certain concentration of serum (preferably within 5%) can be appropriately taken to culture, such as adenovirus, so whether it is necessary to add serum.

Cell count. The number of inoculations is determined according to the counted quantity and culture volume. Plating or passage has an approximate range of cell numbers, and the amount of culture medium used is determined according to this.

It is recommended that you better buy ready-made powder, water can be steamed with four times, and it can be used directly after autoclaving after mixing, which is very convenient. If you don't feel at ease, you can add some antibiotics. If you can, you can also buy liquids directly.

Add deionized water to 1000ml and adjust the pH value to 7Prepare ten 1ooml vials, 1L volumetric flasks, soak acid treatment, buy packs of PBS, generally one pack with one liter. After filling with volumetric flasks, divide into ten vials and plug tightly with stoppers.

Then insert the needle into each plug. Put it in an autoclave and sterilize.

It should be used to observe the pH of the solution. In the laboratory, too much acid or alkali may kill the cells, and the medium or buffer solution needs to be changed.