Spiked-in purified EGFR to serum is accurately detected by the EGFR SOMAmer assay.

<p>Thirty-fold diluted serum samples were appropriately spiked with three different amounts of purified EGFR ECD (final concentration of 30, 150, and 300 ng/mL plus the endogenous serum EGFR ECD). We then performed the EGFR SOMAmer assay followed by the qPCR. The percent recovery is calculated by dividing SOMAmer-measured EGFR by the expected EGFR level (spiked plus endogenous serum EGFR level), multiplied by one hundred. The codes on the X-axis represent sample number and concentration of spiked EGFR. For example, S_1_300 is serum sample #1 with 300 ng/mL of spiked purified EGFR protein. Each sample was measured three times. The error bars represent standard deviations.