The quality and quantity of DNA extracted from the tumour cells is the key to successful downstream analysis. A poor DNA extraction method can lead to increased assay failure and increase the risk of false positive and false negative results
DNA extraction
- Extraction methods need to be robust, reliable and yield as much DNA as possible
- Many DNA extraction methods are available, including kit-based methods, eg QIAamp® DNA minikit (Qiagen)
DNA quantification
- DNA quantification is optional, but may be useful for prioritising exons for screening and troubleshooting assay failure
- Quantitative PCR (Q-PCR) is more accurate than spectrophotometry
- Q-PCR measures only the amplifiable DNA in a sample so it is also a measure of DNA quality. DNA that has broken down during storage is therefore accurately quantified
