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Cell Culture Media
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Information |
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BIOCHROM liquid, and powdered cell culture
media are standardized according to the original formulation as
recommended by the "Tissue Culture Association" (Morton, H.J.
In vitro 6, 89 [1970] and Morton, J.J. et al.
In vitro 8, 106 [1972]). Quality of chemicals used meet in
general the standards "pro analysi", and "Ph.Eur.", resp. Any
modifications from the original formulation are indicated on the
label (e.g. w/o NaHCO3.
Defined cell culture media generally consist of four basic chemical
groups: amino acids, carbohydrates, anorganic salts, and vitamins.
- Amino acids (both essential and non-essential) are required for
protein biosynthesis. Essential amino acids can not be synthesized
by the cell and must be supplied exogenously in the formulation.
Non-essential amino acids, on the other hand, depending on the
metabolism of individual cells, may be synthesized by the cell and
are not required in the formulation. However, a formulation that
provides non-essential amino acids, may minimize the metabolic
burden on the cell, thus allowing the cell to proliferate more
rapidly or to produce a desired end-product more efficiently.
- Glucose is the most common carbohydrate used in mammalian cell
culture. It provides the major energy or carbon source for
biosynthesis. Through glycolysis, glucose is broken down to pyruvate,
which is converted to essential metabolites, and metabolic waste
products in the citric acid cycle. Some media also contain sodium
pyruate as a carbon source. Galactose, which metabolizes to lactic
acid at a slower rate, is sometimes substituted or used with
glucose. This prevents excessive lactic acid accumulation and pH
shift caused by the metabolic conversion of glucose to lactid acid.
- Inorganic salts are essential to cell growth and maintenance. They
provide major ions in the form of sodium, magnesium, potassium,
calcium, phospate, chloride, sulphate and bicarbonate. Inorganic
salts also help to maintain the cellular membrane by controlling the
osmotic pressure. Additionally, they act as a buffer to protect
cells from sharp pH fluctuations due to metabolite waste products.
- Vitamins are generally included in all formulations and function
as catalysts or substrates to facilitate or control certain
metabolic functions. Most cells require the B vitamins. Other
vitamins or coenzymes may be required by some cells and are,
therefore, included in some cell culture media.
- Most cell culture media contain phenol red as pH indicator that
allows visual observation of pH change in the media due to cell
metabolism or environment factors. Other organic or inorganic
components are often included in cell culture media to provide for
specific nutritional or other requirements affecting cell growth. As
serum-free media are being developed, an increasing number of
components once contributed by serum are being replaced by
chemically defined components.
POWDERED MEDIA
BIOCHROM
instamed®
powdered media and salts are produced in specially designed particle
reduction or blending equipment to control bioburden and the
migration of inert materials into the product. Powdered media and
salts are extremely hygroscopic and must be protected from
atmospheric moisture; they are, therefore, packed into sealed glass
(1 liter) or high density polyethylene plastic bottles (5 - 50
liters). Custom or large packag sizes are available on request.
instamed®
powdered media should remain sealed and stored at +2 - +8°C in its
original container.
Powdered media do not contain sodium bicarbonate. For additional use,
the respective concentrations can be sent on request (also the
"General preparation instructions for
instamed®
powdered media).
PREPARATION OF (10x) LIQUID MEDIA
The dissolving technique is essentially the same (add sterile water
at +20 - +37°C to powder medium up to volume, stir mixture to
complete dissolution, sterilize b means of filtration). Please be
aware that concentrated media preparations do not contain sodium
bicarbonate.
Media that can be concentrated (10x) without any problems:
Medium 199
Ham's F-10 medium
Ham's F-12 medium mod.
Certain limitations apply for:
BME Basal Medium Eagle
MEM Minimum Essential Medium (Eagle)
Dulbecco's MEM mod
RPMI 1640 medium
(10x) concentrated solution is only possible with a pH value less
than 2. Otherwise, (5x) or (2x) concentrations must be used instead,
depending on the cystine/tyrosine concentration of the medium.
Concentrated solutions are not recommended for:
Leibovitz L-15 medium
LIQUID MEDIA
Equipment used to manufacture liquid products is designed
specifically to prevent bioburden and endotoxin contamination as
well as the migration of foreign materials (e.g. filter material,
heavy metals or plasticizers) into the product. Water used to
manufacture liquid media, salts and reagents meet the criteria
published in the Ph.Eur. for WFI ("Water for Injection"), processed
by the Cyclodest technique. Liquid products are membrane sterilized,
and aseptically dispensed into 100 ml, 500 ml, or 1000 ml bottles.
Larger packing sizes (5 - 1000 liters) are available on request. All
manufacturing processes and facilities are qualified and validated
to ensure consistency and suitability for intended use. A
Certificate of Analysis describing release criteria and actual test
results is available on request for every single production lot. The
majority of non-concentrated media products do contain sodium
bicarbonate or HEPES, resp. Due to limited stability at +2 - +8°C,
however, they do not contain L-glutamine, nor serum, nor antibiotics.
Prior to use, L-glutamine from a stock solution (L-glutamine, 200 mM,
cat.no. K 0280 to K 0283) needs to be added to these media. The
appropriate volumes of L-glutamine can be sent on request.
STABILITY OF L-GLUTAMINE IN LIQUID MEDIA
L-glutamine is not stable in dissolved form, if stored at +2 - +8°C,
or higher temperatures. Due to cyclisation of L-glutamine, toxic NH3
is formed. Cell culture media containing L-glutamine and L-glutamine
itself must, therefore, be stored at -20°C. As a substitute for
L-glutamine, which limits the shelf life of media, dipeptides
containing L-glutamine can be used as a source. They are stable for
extended time, even at room temperature. Cells can readily
metabolize it into L-glutamine by cleaving the inherent peptide
binding. L-alanyl-L-glutamine (Ala-Gln) or glycyl-L-glutamine (Gly-Gln)
are used in media, with the acetylated form of ac-Ala-Gln being more
stable. BIOCHROM offers the most common cell culture media in a
version containing "stable glutamine" (cat.nos. starting with FG...).
FLAVIN IN CELL CULTURE MEDIA
All commercially available cell culture media do contain 0.01 to 1.0
mg/l of flavines, due to their vitamin nature (in particular
riboflavin, or vitamin B2.
However, flavines serve as potent photo sensibilisators, even if
exposed to visible light. Absorbed light energy will be transferred
by this sensibilisator to oxygen molecules. Unsaturated organic
substrates may react with formation of toxic hyper- and peroxides,
if exposed to this aggressive form of oxygen. To avoid this harmful
effect on the media quality, media may be packed either in opaque
material, not transparent even for visible light, or flavines have
to be omitted from the media formulation. Necessary amounts may then
be supplemented with the serum (at approx. 0.2 mg/l) or separately
from a stock riboflavin solution.
CUSTOMIZED MEDIA
A customized media service is available with a minimum lot size for
liquid media of 5 liters in either 100 ml or 500 ml bottles. For
powdered media, minimum lot size to guarantee homogeneous mixing of
all components, is 100 liters. Packing sizes available range from
100 x 1 liter to 2 x 50 liters. Delivery time is approx. 3 - 4 weeks
for powdered media, and 6 - 8 weeks for liquid media from date of
receipt of order. Please send us your detailed formulation
in writing (Customized Media Order Form, see above).
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+32 (0) 16
58 90 45 
+32 (0) 16
50 90 45
