A geneticist walks into a room . . .

 Carolyn Peluso, Ph.D.

Imagine a dimly lit auditorium; it is 1966 and the founding fathers of cell culture fill the audience. It’s a packed room of men in grey suits with thin black ties. One great man of science lounges confidently in a seat towards the back cleaning his horn-rimmed glasses on his jacket, while another great man of science dozes unashamedly in the front row. Into our scene walks the geneticist Stanley Gartler. He makes his way to the podium and announces that the myriad new cell lines they have gathered there to discuss - the cell lines that represent not only an array of cell types and tissues, but the brilliance of the men seated before him . . . are mostly just HeLa cells grown in new media with new labels.

HeLa cells

I like to think of those stoic, staid scientists booing and throwing their slide-rules at the podium (although in reality they just sat there in stunned silence). Nevertheless, the intensity of the scene led one scientist to later remark “He [Gartler] showed up at that meeting with no background or anything else in cell culture and proceeded to drop a turd in the punch bowl.”*

How could this happen? To answer this question, we need to go back to the beginning. Sterile techniques were in their infancy when many of the “new” cell lines were “immortalized.” Couple that with an understandable ignorance of the HeLa cell’s heartiness, and no reliable method to verify the molecular identity of cells, and it isn’t difficult to understand how this situation arose.

It is more difficult, on the other hand, to understand how the problem of misidentified and contaminated cell cultures could persist to the present day - and yet it does. There are several published lists of cell lines that are known to be contaminated (most often with HeLa cells) or misidentified, but that are still in use. In fact, data obtained through the use of misidentified or contaminated cell lines have been used to support clinical trials, grant applications, U.S. patents and publications.

Once again, we find ourselves asking, “how could this happen?” There are many causes, but here are a few likely explanations:

• Using multiple cell lines in the lab or growing cells on a non-human cell feeder layer increases the likelihood of cross-contamination.

• Cells that have been passaged many times can accumulate new mutations, which can contribute to experimental variability.

• Simple human error accounts for many of the contaminated and misidentified cell cultures in use today. Importantly, these errors can be propagated if the contaminated cell line is shared between investigators.

There is no good way to avoid the scenarios described above, but we can avoid the problems associated with them if we stop periodically to authenticate our cell lines. Our next blog post will provide a detailed description of the resources available to help you do just that. Nobody wants to go back to that dimly lit auditorium of 1966, but it will be difficult to make solid progress forward without addressing cell line contamination and misidentification head-on.

*Robert Stevenson, as quoted in The Immortal Life of Henrietta Lacks, Rebecca Skloot, New York: Random House, 2010.