Chemically defined media are useful when studying the minimal requirements of microorganisms and for a variety of physiological studies. Furthermore, these media are useful in in vitro cell cultures of human and animal cells.
What is an example of a chemically defined media?
Chemically defined media are useful when studying the minimal requirements of microorganisms and for a variety of physiological studies. Furthermore, these media are useful in in vitro cell cultures of human and animal cells. Glucose salt broth is one example of such media. Peptone broth is another example. What are Complex Media?
What is the importance of chemically defined media in microbiology?
Chemically defined media are useful when studying the minimal requirements of microorganisms and for a variety of physiological studies. Furthermore, these media are useful in in vitro cell cultures of human and animal cells. Glucose salt broth is one example of such media.
What is a chemically defined medium?
A chemically defined medium is a growth medium suitable for the in vitro cell culture of human or animal cells in which all of the chemical components are known. Standard cell culture media commonly consist of a basal medium supplemented with animal serum (such as fetal bovine serum, FBS) as a source of nutrients and other ill-defined factors.
What is the chemical composition of complex media?
Complex media are a type of media that contain complex materials which are of biological origin such as blood, milk, yeast extract, beef extract, etc. Hence, the chemical composition of complex media is unknown.
Misuse of the term chemically defined media
Other variants of serum-free/defined media include
What is a chemically defined medium used for?
A chemically defined medium is a growth medium suitable for the culture of microbes or animal cells (including human) of which all of the chemical components are known.
What is chemically defined media in microbiology?
Cell Culture Media in Bioprocessing Chemically-defined (CD) media consist of materials that are either molecularly homogenous or mixtures of characterized and quantitated ingredients [9].
When would Defined media be used?
A defined medium is a minimal medium (Table 4a) if it provides only the exact nutrients (including any growth factors) needed by the organism for growth. The use of defined minimal media requires the investigator to know the exact nutritional requirements of the organisms in question.
Which of the followings is an example of chemically defined media?
Chemically defined media is composed of exact amounts of chemically pure, specifically identified organic or inorganic components. Examples include glucose salt broth or inorganic synthetic broth.
Which one is better chemically defined media or complex media?
For all these parameters the degree of reproducibility achieved by using a chemically defined liquid medium was substantially better than that using batches of complex medium from a single supplier. Even larger variations in these parameters resulted when different suppliers were used.
Do you think humans could exist on a chemically defined media at least under laboratory conditions Why do you think so?
Could humans exist on chemically defined media, at least under laboratory conditions? Humans would probably not be able to exist on chemically defined media, unless other organisms lived in the same media with them. Humans reply on microbes and nutrients from other living organisms to survive.
What types of media are used for urine culture?
It has been recommended that routine microbiological processing of urine specimens include quantitative plating onto blood agar medium along with a selective and differential agar such as MacConkey agar for gram-negative organisms.
What is the difference between defined and undefined media?
A Defined medium is a relatively simple medium that is made up of specific chemicals at known concentrations. An Undefined medium is composed of mixtures of yeast cell extracts or enzymatic digests of protein; the exact amount and kinds of nutrients present in the medium are not known.
What is one potential drawback to using chemically defined media?
A major drawback from the use of serum is the wide range of possible contaminants. Protein concentration found in media containing 10% serum has a range of 6,200-10,000 mg/L, where the concentration for a defined recombinant protein produced in mammalian cells ranges from a few mg/L to 1,000 mg/L (1).
Which of the following was the first widely used chemically defined medium?
Which of the following was the first widely used chemically defined medium? Explanation: The Eagle's basal media was developed in 1955, by Harry Eagle. The DMEM (Dulbecco's modified Eagle's media) is medium developed by Dulbecco and Vogt, and published in 1959.
What is the difference between defined and undefined media?
A Defined medium is a relatively simple medium that is made up of specific chemicals at known concentrations. An Undefined medium is composed of mixtures of yeast cell extracts or enzymatic digests of protein; the exact amount and kinds of nutrients present in the medium are not known.
Is MacConkey agar chemically defined or complex media?
Amounts of individual components are undetermined and variable. Nutrient broth, tryptic soy broth, and chocolate agar, are all examples of complex media. Selective media are used for the growth of only selected microorganisms. An example of a selective medium is MacConkey agar (Table 9.1 & Figure 9.26).
What are the types of media in microbiology?
These are classified into six types: (1) Basal media, (2) Enriched media, (3) Selective (4) Indicator media, (5) Transport media, and (6) Storage media.
What are the constituents of a chemically defined media?
The constituents of a chemically defined media include: a basal media (such as DMEM, F12, or RPMI 1640, containing amino acids, vitamins, inorganic salts, buffers, antioxidants and energy sources), which is supplemented with recombinant albumin, chemically defined lipids, recombinant insulin and/or zinc, recombinant transferrin or iron, selenium and an antioxidant thiol such as 2-mercaptoethanol or 1-thioglycerol. Chemically defined media that are designed for the cultivation of cells in suspension additionally contain suitable surfactants such as poloxamers in order to reduce shear stress caused by shaking and stirring.
What is defined media?
The term 'defined media' can also be used to describe this type of media. Media formulations containing the media supplement B27 (supplied by Invitrogen) are often erroneously referred to as chemically defined media (e.g. Yao et al., 2006) despite this product containing bovine serum albumin ...
What is the difference between serum based media and chemically defined media?
There is a clear distinction between serum-based media and chemically defined media. Serum-based media may contain undefined animal-derived products such as serum (purified from blood), hydrolysates, growth factors, hormones, carrier proteins, and attachment factors. These undefined animal-derived products will contain complex contaminants, such as the lipid content of albumin. In contrast, chemically defined media require that all of the components must be identified and have their exact concentrations known. Therefore, a chemically defined medium must be entirely free of animal-derived components and cannot contain either fetal bovine serum, bovine serum or human serum. To achieve this, chemically defined media is commonly supplemented with recombinant versions of albumin and growth factors , usually derived from rice or E. coli, or synthetic chemical such as the polymer polyvinyl alcohol which can reproduce some of the functions of BSA/HSA.
What is standard cell culture media?
Standard cell culture media commonly consist of a basal medium supplemented with animal serum (such as fetal bovine serum, FBS) as a source of nutrients and other ill-defined factors. The technical disadvantages to using serum include its undefined nature, batch-to-batch variability in composition, and the risk of contamination. ...
What is a chemically defined medium?
Jump to navigation Jump to search. A chemically defined medium is a growth medium suitable for the in vitro cell culture of human or animal cells in which all of the chemical components are known. Standard cell culture media commonly consist of a basal medium supplemented ...
What are the contaminants in animal derived products?
These undefined animal-derived products will contain complex contaminants, such as the lipid content of albumin. In contrast, chemically defined media require that all of the components must be identified and have their exact concentrations known.
Can fetal bovine serum be used in a chemically defined medium?
Therefore, a chemically defined medium must be entirely free of animal-derived components and cannot contain either fetal bovine serum, bovine serum or human serum.
What is chemically defined media?
What are Chemically Defined Media? Chemically defined media or synthetic media are a type of media that contains a known chemical composition. It is because this type of media contains pure chemicals or defined chemicals. Hence, the chemically defined media contain exactly known chemical composition. These media only provide the exact nutrients ...
What are the Similarities Between Chemically Defined and Complex Media?
Chemically defined media and complex media are two main types of culture media that allow the growth of microorganisms especially bacteria.
What are Complex Media?
Complex media are a type of media that contain complex materials which are of biological origin such as blood, milk, yeast extract, beef extract, etc. Hence, the chemical composition of complex media is unknown. Since complex media contains complex materials, they are rich in nutrients and provide a full range of growth factors. Thus, these media help to grow microorganisms that have complex nutritional requirements.
What is the purpose of culture media?
The culture medium is a solid, semi-solid or liquid substrate that is rich in nutrients and other necessary elements and supports the growth of microorganisms . We carry out isolation, identification, and maintenance of microorganisms on culture media. There are different types of culture media depending on the composition and use. Chemically defined media and complex media are two main types of these. Chemically defined media contain pure biochemical; hence, the chemically defined media contain exactly known chemical composition. On the other hand, complex media contain complex materials such as blood, milk, beef extract, yeast extract, etc., so the chemical composition of the complex media is unknown.
What is culture medium?
The culture medium is a solid, semi-solid or liquid substrate that is rich in nutrients and other necessary elements and supports the growth of microorganisms. We carry out isolation, identification, and maintenance of microorganisms on culture media. There are different types of culture media depending on the composition and use. ...
Why are complex media important?
Since complex media contains complex materials, they are rich in nutrients and provide a full range of growth factors. Thus, these media help to grow microorganisms that have complex nutritional requirements. Figure 02: Blood Agar.
What are the different types of culture media?
There are different types of culture media depending on the composition and use. Chemically defined media and complex media are two main types of these. Chemically defined media contain pure biochemical; hence, the chemically defined media contain exactly known chemical composition. On the other hand, complex media contain complex materials such as ...
Why add antibiotics to medium?
adding a certain antibiotic to the medium to inhibit the growth of other organisms.
Is glucose broth a chemically complex media?
glucose broth. While chemically complex media is unknown and can vary from batch
What are some examples of chemically defined media?
Examples include glucose salt broth or inorganic synthetic broth.
What are some examples of complex media?
Examples include Nutrient Broth/Agar, Tryptic Soy Broth/Agar, and Blood agar. What is enriched media and give an example.
What is an enriched media?
Enriched media contain the nutrients required to support the growth of a wide variety of organisms, including some of the more fastidious ones. They are commonly used to harvest as many different types of microbes as are present in the specimen.
When is a substrate oxidized?
17. Know that a substrate is oxidized when it loses a hydrogen ion and its electron. Know that an electron acceptor is reduced when it gains the hydrogen ion and its electron, lost by the substrate.
What is blood agar used for?
Blood Agar is a general purpose enriched medium often used to grow fastidious organisms and to differentiate bacteria based on their hemolytic properties.
What is the instrument used to measure the intensity of light scattered at 90 degrees?
The instrument used for measuring it is called nephelometeror turbidimeter, which measures the intensity of light scattered at 90 degrees as a beam of light passes through a water sample
What allows certain types of organisms to grow and inhibit the growth of other organisms?
Selective media allow certain types of organisms to grow, and inhibit the growth of other organisms
What is minimal defined media?
Minimal defined media. Amino acid solution A contains all required amino acids. A minimal defined medium can be created by omitting amino acid solutions B–E.
How much CDM to add to 60 mm dish?
Transfer all aggregates to a 60-mm dishes. Add additional 5–10 mL of differentiation CDM to the dish.
What is the best media for tetrahymena growth?
Consistent growth of Tetrahymena cells in synthetic, chemically defined media was first shown by Kidder and Dewey (1951) and provided a controlled means of examining cell nutritional requirements. The modified chemically defined media (CDM, Table II ), initially described by Szablewski et al. (1991), support rapid growth similar to that observed in PP media (2 h doubling time at 37 °C), and cell concentrations of up to 10 6 cells/mL. Amino acids in group A are required for growth, but minimal chemically defined media (minimal CDM) can be prepared by omitting amino acids contained in solutions B-E in the CDMA recipe shown in Table II. Minimal CDM is useful for working with auxotrophic mutants ( Sanford and Orias, 1981 ), but cell doubling time in minimal CDM is slightly slower than that in complete CDM (∼ 2.5 h at 30 °C). CDM will support indefinite propagation by serial transfer provided that the initial inoculum concentration is at least 500 cells/mL. However, lower concentrations of cells transferred to CDM will not survive, perhaps as a result of a need for a critical initial cell density to condition the medium with required autocrine factors ( Christensen et al., 1995, 2001; Rasmussen et al., 1996 ). If an inoculum of less than 2500 cell/mL CDM medium is necessary, the medium should be supplemented with 7.5 μM hemin to ensure cell viability. Hemin can be prepared as a stock solution by dissolving in 0.01 N NaOH and autoclaving ( Christensen and Rasmussen, 1992 ). Alternatively, Hagemeister et al. (1999) suggested that Tetrahymena cell death in CDM inoculated with a low concentration of cells is not apoptotic, but is rather the result of accidental cell lysis at the medium–air interface. They provide an alternate CDM recipe (CDMC, Table II) that permits the growth of low cell inoculum or single cells in the presence of an air–medium interface without the addition of any supplements. However, the doubling time in CDMC is 3.5 h at 36 °C, considerably slower than that in CDM. Initial cell concentration is not an issue in PP and bacterized media, which provide adequate amounts of any growth factors necessary for autocrine regulation of cell survival and support strong cell proliferation growth even in single-cell subcultures.
What is contact inhibition?
The phenomenon of ‘contact inhibition’, discovered by Abercrombie, 107,108 provides an important basis for the mechanism of growth control in normal cells. Human diploid fibroblast WI38 displays clear contact inhibition, that is, cell growth is arrested when cells touch each other. Recently, the phenomenon was reinvestigated to determine (1) the molecular mechanism of cell contact and (2) whether ganglioside involved in cell contact blocks FGFR function, in analogy to previous process as in Ref. 106 It was found that tyrosine kinase of FGFR is strongly inhibited by GM3/CD9/CD81 complex when cells were in contact and growth was arrested. In actively growing cells not in contact, GM3/CD9/CD81 complex does not inhibit FGFR tyrosine kinase. It is important to note that FGFR has preferential binding ability to GM3, but not to other gangliosides or GSLs. An overall mechanism for contact inhibition of WI38 and other cell types is illustrated schematically in Figure 11 and explained in its legend.
Is freezing medium safe?
Chemically defined media are safer in clinical practice and we have now compared serum-containing freezing medium (as used in our earlier study)16 with PROH–sucrose as the cryoprotectant, to medium in which serum has been replaced by human serum albumin (J.G. Hreinsson et al, unpublished results).
Overview
The advantages of chemically defined media
• Avoidance of batch to batch variation of bovine serum or albumin, which causes inconsistency in growth-promoting properties.
• Low protein content, which can hinder product purification.
• Elimination of the risk of contaminants—viruses, mycoplasma, prions from animal-derived products which may be transmitted to the end product used by humans, e.g., bovine spongiform encephalopathy (BSE) or mad cow disease.
Classes of media
Animal culture media can be divided into six subsets based on the level of defined media (Jayme and Smith, 2000): From lowest definition to highest these are:
• Serum-containing media (commonly 10-20% FBS)
• Reduced-serum media (commonly 1-5% FBS)
• Serum-free media (synonymous with Defined media)
Misuse of the term chemically defined media
The term chemically defined media is often misused in the literature to refer to serum albumin-containing media. The term 'defined media' can also be used to describe this type of media. Media formulations containing the media supplement B27 (supplied by Invitrogen) are often erroneously referred to as chemically defined media (e.g. Yao et al., 2006) despite this product containing bovine serum albumin (Chen et al., 2008) using the above definitions this type of media is referr…
Other variants of serum-free/defined media include
Animal protein-free media, containing human serum albumin, human transferrin, but potentially animal-derived insulin and lipids.
Xeno-free media, containing human serum albumin, human transferrin, human insulin, and chemically defined lipids.
See also
• Biological immortality
• Cell culture assays
• Microphysiometry
• Organ culture
• Plant tissue culture
External links
• cellasys procedure for preparation of chemically defined medium
• GIBCO Perspectives in Cell Culture
• Invitrogen Guide to Serum-Free Culture
• TNC Bio list of Chemically Defined products