What is stock culture?

What is stock culture?

Reference strains for the development and validation of new methods. Pathogens and spoilage organisms lated during routine testing or in the investigation of contamination problems. Cultures used in microbiological assays. Isolates required for research purposes.

What is working stock culture?

Working Stock Cultures: A working stock culture is growth derived from a reference stock culture. Guidelines and standards outline how working stock cultures must be processed and how often they can be subcultured.

What does subculture mean in microbiology?

subculturing
In biology, a subculture is either a new cell culture or a microbiological culture made by transferring some or all cells from a previous culture to fresh growth medium. This action is called subculturing or passaging the cells.

How do you create a stock culture?

Inoculate a culture flask containing 5-10 ml of liquid medium with a single bacterial colony and grow the culture overnight. 2. Transfer 3.4 ml of the overnight culture to a sterile vial containing 0.6 ml of sterile glycerol. Place the cap on the vial and mix the contents thoroughly by vortexing.

What is the importance of stock cultures?

Stock cultures of microorganisms kept in a laboratory provide the organisms required for conducting experiments (Fig. S1). As such, the stock cultures are extremely important resources, and should be maintained in a manner that ensures their long-term persistence.

What do you understand by subculture?

According to Oxford English Dictionary (the OED), subculture, means “an identifiable subgroup within a society or group of people, especially one characterized by beliefs or interests at variance with those of the larger group”. Originally “subculture” indicated a particular group of people and their culture.

How do you subculture bacteria?

Sub-culturing is a procedure of transferring of microorganism into fresh nutritive medium from its stock culture. It includes transfer of culture from slant to slant, slant to plate, plate to plate, plate to slant, solid medium to broth, and broth to solid media.

What is a stock culture used for?

A culture of a microorganism maintained solely for the purpose of keeping the microorganism in a viable condition by subculture, as necessary, into fresh medium.

How do you maintain stock cultures?

Preserving Stock Cultures A popular method for preserving microorganisms is through lyophilization, or freeze drying. This method is best for long term storage. The lyophilization process requires costly equipment including a lyophilizer, vacuum pump, generator, etc.

Where are stock cultures stored?

fridge
5 A stock culture prepared from reference stock in a plate or a slant can be stored at room temperature or the fridge (2- 8°C) for 4 weeks and is used to prepare working cultures. Working cultures must be renewed on a weekly basis and daily subcultures are prepared fresh from them.

What is subculture in popular culture?

Subculture and Counterculture. A subculture is just what it sounds like—a smaller cultural group within a larger culture; people of a subculture are part of the larger culture but also share a specific identity within a smaller group. Thousands of subcultures exist within the United States.

What is the definition of a stock culture?

Definition: – Stock cultures are those cultures of microorganisms that are stored or maintained for future use in such a fashion that their growth and productive capacities remains unaltered.There are two types of stock cultures: (i) working stocks and (ii) Primary stocks.·

How is stock culture maintained in a laboratory?

Whatever the size of the laboratory ’s stock culture collection, it is important that it is properly maintained. Traditionally this has been a matter of culturing isolates on agar slants of suitable media and then subculturing onto fresh slants at regular intervals.

Why do you need a good stock culture collection?

There are a number of reasons why a microbiology laboratory needs stock cultures in good condition. The typical stock culture collection may contain isolates that fall into one or more of the following categories: Reference strains for quality control of culture media and methods

What happens to cells in a stock culture?

Thus, primary stock cultures are stored in such a manner as to require the least possible numbers of transfers over a period of time. Death of a high percent of cells in a primary stock culture is not particularly serious, if viable cells can still be recovered for subculture to fresh medium.