Ask the Expert – Cell Culture Basics – Avoiding contamination, cell growth and passaging, and proper storage techniques

By on January 11, 2015
Ask the Expert

Sometimes it’s good to get back to basics. This approach can be especially helpful in cell culture particularly in troubleshooting any culture problems. Do you have questions about aseptic techniques, contamination or the use of anitbiotics? Are you trying to troubleshoot difficulties with your cell growth or viability in culture? Are you struggling with storage, freezing or thawing of cells? If so, now is the time to get some answers. Whether it’s troubleshooting problems in your culture or just getting clarification on various cell culture techniques – visit this week’s Ask the Expert session and submit your questions.

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Daily Tips

Monday’s Tip:

Do you routinely equilibrate your media to 37C before using it?

Monday’s tip is that if you do, you may be doing more harm than good. Instead place you media in a dark drawer or cabinet and just take the chill off. Generally speaking, unless you are doing a special procedures or using large volumes of media, there is no advantage to pre-warming media.  Given the large surface area of a dish or flask and the relatively thin layer or media, media will cool down significantly when you take you vessel out of the incubator.  Probably after that you put your dish or flask on a room temperature microscope stage or biological safety cabinet which further speeds cooling from the incubator temperature.  The  “more harm than good” part of this tip is that there is a natural decay of critical media components such as glutamine, and others, that is sped up by 37C incubations and if you use a waterbath without a cover light can damage the media further.

Tuesday’s Tip:

Are you looking for a simple way to boost productivity in many cell culture systems including recombinant protein expression?

Since many cells get limited amounts of energy (ATP) from the metabolism of glucose, other energy sources are needed.  Once such source of energy comes from the metabolism of glutamine.  Many cell types get somewhere between 40% to 70% of their energy from glutamine.  The problem with glutamine as an energy source is that is is unstable.  Glutamine spontaneously breaks down and ihas a half-life of 4-5 days at 37C.  A better alternative to glutamine is GlutaMAX I.  This L-Alynl-L-Glutamine  dipeptide is very stable and does not breakdown in medium as monomeric glutamine.  This small change can make dramatic differences in the energy status of a cells and therefore increase productivity. I f you try GLutaMAX I there is not adaptation necessary you can just substitute directly.

Wednesday’s Tip:

You might want to gain knowledge about the latest developments in cell line authentication.

Recently NIH and others have proposed Principles and Guidelines for Reporting Preclinical Research (http://www.nih.gov/about/reporting-preclinical -research.htm).  Most journals will require some diligence on the part of the cell culture researcher to qualify and identify the cell type they are using.  Find out which journals at http://www.nih.gov/about/endorsing-journals.htm.  A very good LinkedIn group you may want to join is Cell Line Authentication then have a link on their site the links provides a list to over 400 cell lines that are currently known to be cross-contaminated of misidentified.  If you can not find the link the reference is as follows.  Capes-Davis A, Theodosopoulos G, Atkin I, Drexler HG, Kohara A, Macleod RA, Masters JR, Nakamura Y, Reid YA, Reddel RR, Freshney RI (2010) Check Your Cultures! A list of cross-contaminated or misidentified cell lines.  Int J Cancer 127(1) 1-8. PMID 20143388.

Thursday’s Tip:

Know your microscope.

To get the best out of cell culture, be sure to know how to use your microscope. Most have at least an inverted phase contrast microscope.  Be sure it is maintained and that you low how to use it and get the best images possible.  ATCC notes that it is important to photo-document your cells at different stages of confluencey. Do you know what phase rings go with what objectives on your microscope?

Friday’s Tip:

Have “conditioned media” for each cell type you grow.

Conditioned media is media that has been used to grow cells. Each conditioned media is specific for a specific cell type and should be kept separate.  Conditioned media is made by growing a sub-confluent culture in fresh growth media overnight.  The next morning, using sterile technique, remove the partially used media and place in a sterile tube.  Then centrifuge to remove any cell debris.  This conditioned media has had some nutrition used by the growth of cells overnight but importantly those cells also added some compounds to the media as they grew. These factors can be useful if your cells begin to grow poorly.  A 50%/50% mixture of fresh and conditioned media is very useful when growing cells at very low density or when isolating individual cells.  For freezing cells us he mixture and add DMSO to about 7.5%.  Once you have made conditioned media you can freeze it in small volumes for long-term storage.

Be sure to check in to see our daily cell culture tips and tricks.

This Ask the Expert Session is Sponsored by Life Technologies and hosted by Timothy Fawcett, Ph.D.  Dr. Fawcett has been in the biotechnology business for over 30 years.  Trained as a biochemist he has held senior positions in both academics and industry and has been a mentor to many young scientists throughout his career.  For the last 12 years Dr. Fawcett has been the Director of the BioTechnical Institute of Maryland (BTI) a non-profit institute located in Baltimore, Maryland.  He is also the Founder and Director of BioSciConcepts, a social venture of BTI that provides hands-on training for professional scientists in cell culture, baculovirus based expression, as well as topics such as molecular biology, PCR and real-time PCR. BioSciConcepts is an internationally recognized provider of expertise in the biological sciences and has provided consultation services to several small and large biotechnology companies.

Please take advantage of the opportunity to ask our expert a question and participate in a lively discussion of Cell Culture Basics!

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Looking for a more comprehensive study of cell culture basics:

If you are looking for a comprehensive course on cell culture basics, see Gibco’s Cell Culture Basics Course and Certification program. Learn the basic techniques for effective, reproducible laboratory cell culture, including optimized procedures and products that will help you get the consistency your lab work demands.

Cell Culture Basics is designed to introduce you to the practice of laboratory cell culture, covering topics such as laboratory set-up, safety, and aseptic technique. You’ll also learn basic methods for passaging, freezing, and thawing cultured cells. Upon the successful completion of this course, you will have a basic understanding of the principles and practice of cell culture that you can immediately apply to your research projects. Aspiring cell culturists, experienced researchers, as well as lab managers and principal investigators may all find value in Gibco® Cell Culture Basics. Students completing this course will be eligible to take the free Gibco® Cell Culture Basics certification test and earn the corresponding certificate.

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