DEFINITION: It is a mixture of salts, amino acids, vitamins and other components that are essential for cellular growth.

ACTION: Acts like a nutritive solution in cell culture.

PRODUCT SPECIFICATIONS: It is applied for human and other animal cell culture. There are two presentations: powder and liquid. The powder medium is stable for more than 24 months if well locked in freezer and promotes constant results at long term. MEM medium is considered a nutritional standard solution for cell culture because it has the basic nutrients for cellular maintenance. It may be available with essential and non-essential amino acids or with variation of any other component.

ADVANTAGES: Tested in at least three different cellular lineages and also in lymphocyte culture. Ph and osmolality are always determined. Each lot is only discharged if within proper limits. The medium also promotes a great cellular growth.

PHYSICAL-CHEMICAL CHARACTERISTICS:

-Appearance: rosy and homogeneous powder
-Particles size: approximately 20 microns
-Solubility: Limpid solution at concentration to be used (1x)
-pH at 25°C (without NaHCO3): 5.9 + 0.5
-pH à 25°C (with NaHCO3): 7.60 + 0.5
-Osmolality (without NaHCO3): 250 + 5%
-Osmolality (with NaHCO3): 295 + 5%

 

STORAGE: Store the powder or the final solution at 2 to 6°C. If these conditions are not maintained alterations may be observed, such as:

1. Change colour
2. Grainings
3. Insolubility
4. Alteration of pH
5. Incapacity to maintain its integrity under normal conditions.

PREPARATION: MEM medium is extremely hygroscopic and must not be exposure to the environment. Preparations with higher concentrations are not recommended due to the possibility of the formation of precipitate.

1. Measure out tridistillate water to approximately 90% of desired total volume of medium (15-20°C).
2. Add the powder and mix gently into equilibrium. DO NOT HEAT THE WATER.
3. After the powder is completely dissolved, add 2.2 g of sodium bicarbonate 5.6% for one liter.
4. Add antibiotics or other components if desired.
5. If necessary, adjust pH with HCl 1N or NaOH 0.1N, or also CO2.
6. Add tridistillate water to the final volume and filter the medium into sterile container using a 0.22m membrane filter.

PRESENTATION: Powder: bottles with powder for 1, 10 and 50 liters.
Liquid: Bottle with 100 and 500 ml.
STORAGE: 2 to 6°C
SHELF LIFE: 12 months