- Effective maintenance of stock cultures is essential for QC, method validation and research purposes
- Repeated subculturing may eventually lead to contamination, loss of viability and genotypic/phenotypic changes
- Freeze-drying and cryogenic storage are preferred, but may not be practical for smaller laboratories
What are stock cultures?
Stock cultures are microorganisms maintained for the purpose of keeping the microorganisms viable. Maintaining cultures internally may seem like the most cost-effective solution.
What is Stok culture?
stock cul·ture. (stok), 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.
Why is proper documentation important when maintaining stock cultures?
When maintaining stock cultures, it is critical that proper documentation be maintained. This is important for lab organization, as well as audits. In regards to in-house stock cultures, maintaining the paperwork can be a tedious process, especially if a large number of strains are being maintained.
Why do we test the stability of stock cultures?
This verifies the cultures are stable in the storage conditions. Since stability varies from one organism to the next, it is recommended to test the stability of each species. This is another labor intensive step of maintaining stock cultures internally.
What is labelling mistakes?
How are stock cultures stored?
What is a cryoprotectant bead?
How to prepare a colonial growth?
What temperature is liquid nitrogen?
How many passages of culture should be made from the original strain?
How many passages of stock culture should be made?
See 4 more
What does stock culture mean?
[ stŏk ] n. A culture of a microorganism maintained solely to keep it viable for subculture into fresh medium.
What is the advantage of preserving the stock cultures?
The cultures are also less vulnerable to contamination. No specialised, or expensive equipment is required and so the method is suitable for small routine laboratories.
How do you maintain 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.
How long and where should a stock culture be kept?
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 the importance of maintaining a pure culture?
These pure cultures are important to microbiologists as they allow for the study of one species without the worry of contamination from other organisms.
Why is it important to preserve microorganisms?
Given the importance of microorganisms as cell factories in biotechnological applications and as model organisms for the study of various biological processes, the preservation of microorganisms plays a key role in ensuring reproducible results and continuity in research.
How do you prepare a bacterial stock culture?
Bacterial Glycerol StocksPut 0.5ml bacterial culture in a sterile eppendorf tube.Add 0.5ml of sterile 80% (v/v) glycerol soution.Freeze on dry ice or directly into –70oc .Store at –70oC. Cells are best for about 4-6 months, but will probably work ok for a whole year.
How do you maintain anaerobic stock cultures?
Store at room temperature in a candle jar or in a container with a CO2 packet. Store at room temperature. Store in anaerobic conditions at room temperature. Store on chocolate agar at 35°C in microaerophilic conditions.
What is the purpose of a culture medium?
Culture medium or growth medium is a liquid or gel designed to support the growth of microorganisms. There are different types of media suitable for growing different types of cells. Here, we will discuss microbiological cultures used for growing microbes, such as bacteria or yeast.
Why do you have to keep cultures inside the refrigerator?
Bacteria can survive for a short period of time at 4°C. For strains that are used daily or weekly, cultures grown on agar slants or plates can be stored in a refrigerator assuming that precaution has been taken to avoid contamination.
Is there an easy and safe way to maintain stock cultures of fungi?
Most fungi can be preserved, with or without cryoprotectants, in liquid nitrogen or in standard home freezers. With freeze drying, or lyophilization, the fungal cultures are frozen and subsequently dried under vacuum. The method is highly successful with cultures that produce mitospores.
Why culture method is done in laboratory?
Microbial cultures are used to determine the type of organism, its abundance in the sample being tested, or both. It is one of the primary diagnostic methods of microbiology and used as a tool to determine the cause of infectious disease by letting the agent multiply in a predetermined medium.
What is the importance of storing the culture following the proper protocol of storage?
The goal of preserving the cultures is to slow that death rate so that when the culture is revisited, some of the cells are still viable and available for culturing.
Is there an easy and safe way to maintain stock cultures of fungi?
Most fungi can be preserved, with or without cryoprotectants, in liquid nitrogen or in standard home freezers. With freeze drying, or lyophilization, the fungal cultures are frozen and subsequently dried under vacuum. The method is highly successful with cultures that produce mitospores.
How important is maintenance and preservation for microorganisms?
Once a microorganism has been isolated and grown in pure culture, it becomes necessary to maintain the viability and purity of the microorganism by keeping the pure culture free from contamination.
What is the purpose of transferring the cultures to the refrigerator after the incubation period?
If you cannot return to lab during an “open lab” period, then incubate them at room temperature, or arrange to have your cultures transferred to a refrigerator after they grow, so that the culture won't die out before you can finish your experiments.
SOP for Maintenance and Transfer of Stock Cultures
a. Reconstitute the powder with 1ml of sterile distilled water and vortex for 1 min and mix well. b. Add 0.25 ml in the respective fluid medium in duplicate.
Quality matters: stock culture maintenance protocol
Culti-Loops Quality Control Organisms enable quick and safe preparation of ATCC® and NCTC cultures for QC testing. They are ready-to-use bacteriological loops containing gel-stabilised micro-organisms.
Maintaining Stock Cultures In-House: Are You Really Saving in the End ...
Economical solutions have become a growing interest to many people both personally and professionally. Individuals are looking to save money, both at home and at the office. Industries and companies worldwide are seeking innovative and convenient methods for cutting costs, driving productivity, and increasing revenue. In microbiology laboratories around the world, individuals are maintaining ...
What is labelling mistakes?
Labelling mistakes – subculturing a large number of agar slants many times introduces a significant chance of a culture being wrongly labelled
How are stock cultures stored?
After incubation at a suitable temperature, the subcultures are stored in a refrigerator until required, or until the next subculturing is due. This system works up to a point, but it does have some serious drawbacks.
What is a cryoprotectant bead?
Cryoprotectant beads allow routine labs to maintain a stock culture collection simply and at low cost.
How to prepare a colonial growth?
Outline method 1. Prepare a suspension of cells or spores of the isolate to be stored, preferably using an 18 to 24 hour old culture grown on solid medium. The colonial growth is suspended in a cryoprotectant fluid, such as Brucella Broth with Glycerol, in a cryogenic vial containing 20-30 of the porous beads. 2.
What temperature is liquid nitrogen?
The temperature of liquid nitrogen is -196 o C, well below the temperature at which all metabolic activity is thought to cease. As with freeze-drying, not all microbial cultures will survive the process, but those that do may survive for many years. Indeed viability for some isolates may be better than for freeze-dried cultures. However, cryogenic storage is expensive, requires significant amounts of liquid nitrogen and is probably only suitable for larger reference laboratories with extensive culture collections.
How many passages of culture should be made from the original strain?
In fact, the American Type Culture Collection (ATCC) recommends that no more than five passages (subcultures) should be made from the original type strain, with the first passage being defined as the culture prepared from the vial supplied by ATCC.
How many passages of stock culture should be made?
In fact, the American Type Culture Collection (ATCC) recommends that no more than five passages (subcultures) should be made from the original type strain, with the first passage being defined as the culture prepared from the vial supplied by ATCC.
How to maintain stock cultures?
Maintaining stock cultures in-house often requires additional equipment. Purchasing and maintaining equipment is expensive and usually results in the need to purchase additional supplies. For example, preservation of bacteria necessitates purchasing specific media for creating microorganism suspensions. Plus, samples must be stored in small vials which are specifically made for low temperatures. Depending upon the number of samples being stored, a large number of vials may need to be purchased. Additionally, a considerable amount of agar plates will also be required for subculturing.
Why are laboratory reagents important?
These certificates are important because they allow for traceability to the source. Quality control microorganism strains should be treated the same as any other laboratory reagents. A microorganism from a reputable source verifies the correct identity and a limited number of passages. For example, all of Microbiologics ready-to-use microorganism products are traceable to their original source and are only 4 passages or less. When an auditor asks for the origin of a culture, the lab can easily present a certificate from the quality control microorganism’s producer.
How to preserve microorganisms?
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. This process also requires purchasing specific media to create the bacterial suspensions which will be lyophilized. Lastly, and most importantly, hiring or training an employee to conduct the lyophilization process and paying their wage puts a major dent in a laboratory’s already tight budget. In regards to cost-effectiveness, it is probably best to leave the lyophilization process to the experts, such as Microbiologics.
What is stock culture?
Stock cultures are microorganisms maintained for the purpose of keeping the microorganisms viable. Maintaining cultures internally may seem like the most cost-effective solution. However, a deeper financial analysis of the cost of obtaining stock cultures, additional supplies and equipment, and the lab technologist’s time, ...
What are the benefits of purchasing cultures from a reference material producer?
Another benefit of purchased cultures from a Reference Material Producer is the identity is certified and guaranteed. Samples are accompanied by a certificate of analysis which certifies the quantity, viability, and identity. This removes any guess work, and there is no need for a validation.
Why do labs label samples?
Lab personnel spend a great deal of time labeling all the samples, and organizing the samples in storage; this time could be spent doing something more productive. Plus, a minor distraction in the labeling process could cause drastic repercussions. If one microorganism is labeled incorrectly, it could provide false-positive or false-negative results. Releasing products with inaccurate test results in the food industry, clinical setting, pharmaceutical industry, or any industry for that matter, could be catastrophic, even fatal. Ready-to-use microorganism products come in clearly labeled packaging, which greatly decreases the risk of mislabeling, and also saves time.
Why do microbiologists maintain their own stock cultures?
In microbiology laboratories around the world, individuals are maintaining their own stock cultures as a method they feel is more cost-effective. However, in reality it may actually cost ...
What is stock culture?
stock cul·ture. 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.
What medium is used for stock culture?
For long-term maintenance of stock cultures, we found a simple pea-based medium to be very successful.
Does the culture conditions used to maintain coexistence and single species treatments in the first phase of the experiment have an effect on?
This contrast was not significant indicating that, in comparison to the stock cultures, the culture conditions used to maintain the coexistence and single-species treatments in the first phase of the experiment did not have an effect on the census histories.
Why Is Culture Important to a Society?
A healthy prosperous culture is a positive reflection of a diverse community. Culture is vital to the growth and economic progress of society.
How does a healthy culture help a community?
A healthy culture learns to adapt to changes. It can expand and grow without feeling its own core values are threatened. The healthy community may even adopt some parts of a new culture. These new cultural aspects can strengthen the existing ethos and add to its own richness and diversity. This kind of growing and advancing culture can better support its members. It can provide a more stable and nurturing framework for the community, but more importantly, the individuals within the culture.
What is the connection between culture and economy?
Connection Between Economies and Cultures. The culture is the driving force behind a community's economy. The culture provides individuals with specific goals , such as creation and building. The more diverse a culture is, the more economic opportunities and wealth it can have.
How does diversity help you?
Diversity Can Inspire Greater Self-Expression. Diversity can inspire you to find a new way of self-expression. An artist may be inspired by the art of another culture, or discover that a certain aspect of the new culture challenges what they thought they understand about life in general.
What is the biggest threat to a culture?
In strict instances of controlling cultures, the biggest threat is the stifling of individuality. When a person is forced to fall in line with strict cultural mandates, they don't develop discernment or critical thinking.
How does culture influence you?
It's undeniable that your culture influences who you are, your perspective about life and the world at large, and your values. Even your sense of humanity and how you relate to other people are influence by your culture. This type of influence can result in what is commonly called a cultural gap.
What happens if you don't toe the cultural line?
In fact, the person will be ostracized and shamed into conforming to the culture's precepts.
What is labelling mistakes?
Labelling mistakes – subculturing a large number of agar slants many times introduces a significant chance of a culture being wrongly labelled
How are stock cultures stored?
After incubation at a suitable temperature, the subcultures are stored in a refrigerator until required, or until the next subculturing is due. This system works up to a point, but it does have some serious drawbacks.
What is a cryoprotectant bead?
Cryoprotectant beads allow routine labs to maintain a stock culture collection simply and at low cost.
How to prepare a colonial growth?
Outline method 1. Prepare a suspension of cells or spores of the isolate to be stored, preferably using an 18 to 24 hour old culture grown on solid medium. The colonial growth is suspended in a cryoprotectant fluid, such as Brucella Broth with Glycerol, in a cryogenic vial containing 20-30 of the porous beads. 2.
What temperature is liquid nitrogen?
The temperature of liquid nitrogen is -196 o C, well below the temperature at which all metabolic activity is thought to cease. As with freeze-drying, not all microbial cultures will survive the process, but those that do may survive for many years. Indeed viability for some isolates may be better than for freeze-dried cultures. However, cryogenic storage is expensive, requires significant amounts of liquid nitrogen and is probably only suitable for larger reference laboratories with extensive culture collections.
How many passages of culture should be made from the original strain?
In fact, the American Type Culture Collection (ATCC) recommends that no more than five passages (subcultures) should be made from the original type strain, with the first passage being defined as the culture prepared from the vial supplied by ATCC.
How many passages of stock culture should be made?
In fact, the American Type Culture Collection (ATCC) recommends that no more than five passages (subcultures) should be made from the original type strain, with the first passage being defined as the culture prepared from the vial supplied by ATCC.
