In a surprise finding, researchers working with breast cancer cells purchased at the same time from the same cell bank discovered the cells responded differently to chemicals, even though the researchers had not detected any difference when they tested them for authenticity at the time of purchase.
Had the cells been the same, the exposure to chemicals would have produced similar results in the cells. Instead, identical experiments in two different laboratories – one at the Johns Hopkins Bloomberg School of Public Health and another at Brown University – produced very different results, even when the researchers swapped out the cells and replicated their experiment to rule out issues at the respective laboratories. Upon further testing, however, the researchers discovered the cells had been genetically different from the time they acquired them.
Researchers have long worked under the assumption cells purchased from the same lot of a cell bank are clones — after all, they presumably result from divisions of a single cell, and therefore should all carry the same DNA. The reliability of cells is the foundation of much scientific research.
The findings, being published online July 26 in the journal Scientific Reports and discussed at the EuroScience Open Forum (ESOF) in Manchester, England, were made by a research team led by scientists at the Johns Hopkins Bloomberg School of Public Health. Even if this was one bad batch, the discovery raises uncertainty about the reproducibility of experiments using cells researchers have assumed were the same and contained the same DNA. For the researchers, the flawed cells cost them several years of work and close to $1 million in research funding from the National Institutes of Health.
“Every researcher believes that if they use cells from the same line of cells, particularly cells from the same lot of a cell bank, then they have clones that should look and act the same,” says study leader Dr.Thomas Hartung, a professor in the Bloomberg School’s departments of environmental health sciences and molecular microbiology and immunology. “We learned in this study that is not always the case.”