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. Author manuscript; available in PMC: 2013 Jun 15.
Published in final edited form as: Clin Cancer Res. 2012 May 1;18(12):3209–3211. doi: 10.1158/1078-0432.CCR-12-0871

Figure 1.

Figure 1

Mutation detection from blood by BEAMing. Blood samples from patients with metastatic cancer contain free circulating tumor DNA (ctDNA) released into the blood stream from tumor growing at primary or metastatic sites. Specific point mutations in targetable genes of interest such as PIK3CA can be detected in ctDNA using BEAMing technology. Circulating tumor DNA molecules are loaded onto magnetic Beads coated with specific polymerase chain reaction primers for the gene of interest. Polymerase chain reaction is performed on the beads in an oil and water Emulsion (Emulsion PCR)to Amplify the DNA. Fluorescent-tagged probes specific for either the wild type sequence or for particular common point mutations are added and hybridize to the amplified DNA. Magnetic flow cytometry of the beads is performed to detect the fluorescent tag and quantify the number of beads containing mutated DNA. The results suggest BEAMing ctDNA in blood plasma is a sensitive and accurate method for relatively non-invasive assessment of current mutation status in patients with metastatic disease.