Aptamer probes for cancer

摘要

Weihong Tan and colleagues at the University of Florida have developed a way to exploit key molecular differences between two cell types to effectively "pan" for tissue-specific aptamers without prior knowledge of the molecular targets by a process called cell-SELEX. Tan's group mixed a library of random single-stranded DNA molecules--52-mer sequences flanked by 18-mer PCR primer sequences--with a line of cultured leukemia cells called CCRF-CEM. They washed off the unbound aptamers and eluted those attached to the cells. Then they incubated this subset of aptamers with a control cell line and eliminated those sequences that also bound to these cells. The investigators amplified the remaining subset of aptamers and repeated the selection cycle several more times, monitoring the cell-aptamer interactions with flow cytometry.