Nearly 33,000 journal articles rely on misidentified cells lines, according to a recent estimate by a pair of Dutch researchers.
While Serge Horbach and Willem Halffman, both from Radboud University, note that there is an ongoing effort to prevent future contamination of cell lines, they add that the literature already contains numerous papers based on misidentified cells lines. As they report in PLOS One, they attempted to determine the extent to which such cell lines influence published research by focusing on the prevalence of known contaminated cell lines in journal articles. From this, they identified 32,755 articles that used misidentified cells lines and some 500,000 additional papers that cite those articles.
As Derek Lowe points out at In the Pipeline, the number of affected papers is mounting. "The number of papers citing cell lines that are known to be wrong is increasing — perhaps not as a percentage of all scientific papers, but it sure isn't going down, despite numerous warnings and exhortations," he writes.
In their paper, Horbach and Halffman suggest that papers based on misidentified cells lines be tagged with an expression of concern. "If clear and uncontended, the consequences of the misidentification for the article's conclusions could be reported, but otherwise the expression of concern could merely state: 'Cell line X in this study is known to be misidentified and is actually Y. See Z for more information,'" the pair writes.