Low Level Detection of Protein Biomarkers from Cancer Cells

In this application note, we demonstrate a novel method for detecting Prostate Serum Antigen (PSA) from reduced sample volumes. The Nano eNablerTM system is used to create ultraminiaturized antibody arrays with spot sizes from 5-8 μm in diameter occupying 1/100th to 1/1000th the surface area of a conventional microarray (D=100 μm) spot [1]. This PSA level of sensitivity is several orders of magnitude lower than that required for biomedically relevant screening. Furthermore, it requires <1 μl of sample, opening the door to minimally invasive cancer biomarker screening & ultimately single cell diagnostics. Serum PSA and IL-6 (interleukin 6) levels are part of the early detection and prognostic tests for prostate cancer, and provide a good model system for evaluating this detection methodology.