Did you ever have to repeat an entire culture experiment because of microbial contamination? This is a fairly common issue faced by most cell biologists at least once in their lifetime.While much effort has been made to improvise cell culture models and techniques, there is a lot of ignorance towards quality control (QC) measures. High quality cultures require strict measures of quality assurance. QC not only ensures sterility but also helps in generating reproducible and reliable results. Extra caution can also save up a lot of time, money, and effort. Kosheeka provides a range of high quality primary cultures for your research applications so you can be assured of supreme reliability.
Quality control measures for primary cultures
While setting up primary cultures, it is essential to perform routine screening for contaminants starting from the source tissue procurement. Major types of microbial contaminants includefungi, bacteria and mycoplasma. While antibiotics such as penicillin, streptomycin or amphotericin may be added to the culture media, their routine usage is often discouraged. Overuse of antibiotics can make cultures resistant and often mask the presence of severe contaminants. Rather, a focus on aseptic culture techniques maybe more beneficial in the long run. Another contaminant, mycoplasmas are quite resistant to antibiotics and hard to detect. Mycoplasma detection kits based on PCR and ELISA assays are becoming popular these days. In addition, endotoxin testing should also be performed to ensure utmost sterility of your cultures.
Quality of reagents and plasticware
For establishing high quality cultures, one must procure high quality culture-grade reagents from reputed manufacturers. Serum is particularly a source of mycoplasma and viruses. Every batch must be stored at appropriate temperature and tested for contaminants before use. Lot number and date of expiry must be recorded This is also true for culture media, and other reagents such as trypsin. Laboratory grade sterile water must be used for reconstitution of reagents and preparation of buffers.
The key components of aseptic technique are good personal hygiene, sterile handling and sterile workplace. Good personal hygiene encompasses washing hands, wearing caps, masks and a gown before entering a culture room to reduce probability of contaminants. Biosafety cabinets must be wiped with 70% alcohol using lint-free cloths and sterilized with ultraviolet light before and after every use. HEPA Filters must also be cleaned and replaced at regular time intervals. Finally, sterile handling and good culture practices must be ensured at all times to avoid contamination of the cells, reagents or the work area.
Procurement and waste disposal
A particular sourceof contamination is the tissue of origin of the cells. The tissue must be decontaminated before culturing the cells. It is also essential to dispose of the waste safely after proper treatment.
While the importance of record keeping is often neglected, it can help immensely in pin pointing errors and creating disciplined culture practices. Keeping temperature charts for incubators, water bath and refrigerators and maintaining log books for all laboratory equipment are key to good laboratory practices. Moreover, all equipment must be calibrated regularly.