Cell line study

Comprehensive validation of results from individual single cells is not possible due to lack of alternative techniques which may be applied to amplified samples. However, robust cell lines of known karyotype may be used to validate the accuracy of the technique.

BlueGnome has undertaken a blinded study (to be published), which comprised testing of 57 single cells from 5 cell lines. 10 single cells were euploid, and the remaining 47 were aneuploid. The results of the study are summarized below:

Of 57 samples, 51 passed both amplification and array QC (comprising sex-mismatch controls). All gave the correct result. The 6 cells which failed assay quality measurements fell into 3 categories. Firstly, 2 samples produced no amplification products, as determined by electrophoresis, and were not hybridised to microarrays. Secondly, a further 3 samples produced only weak amplification products and were screened by 24sure but failed sex-mismatch control QC. Lastly, 1 cell produced an amplification product of normal abundance, but failed sex-mismatch control QC. No result was reported where sex-mismatch controls failed.

On the basis of this study, the accuracy of the technique is 100% and the QC failure rate is 11%. The sample size of the study was relatively small, however, and an accuracy of 100% is unrealistic. BlueGnome estimates, but does not guarantee, an accuracy of over 95% on the basis of this study.