Microfluidic Device for Aptamer-Based Cancer Cell Capture and Genetic Mutation Detection.

We present a microfluidic device for specifically capturing cancer cells and isolating their genomic DNA (gDNA) for specific amplification and sequence analysis. To capture cancer cells within the device, nucleic acid aptamers that specifically bind to cancer cells were immobilized within a channel containing micropillars designed to increase capture efficiency. The captured cells were lysed in situ, and their gDNA was isolated by physical entanglement within a second smaller-dimensioned micropillar array. This type of isolation allows the gDNA to be retained and purified within the channel and enables amplification and analysis to be performed on the gDNA without the loss of the original template. We developed a technique for selectively amplifying genes from whole gDNA using multiple displacement amplification. The amplified gene samples were sequenced, and the resulting sequence information was compared against the known wild-type gene to identify any mutations. We have tested cervical and ovarian cancer cells for mutations in the TP53 gene using this technology. This approach offers a way to monitor multiple genetic mutations in the same small population of cells, which is beneficial given the wide diversity in cancer cells, and therefore it requires very few cells to be extracted from a patient sample.