Figure 1.

Schematic representation of two-color RCA on antibody microarrays. Two pools of proteins are respectively labeled with digoxigenin (C1, digoxigenin-labeled protein, digoxigenin represented by the triangle) and biotin (C2, biotin-labeled protein, biotin represented by the diamond). Primer 4.2-conjugated anti-digoxigenin (B1) and primer 1-conjugated anti-biotin (B2) bind to captured proteins, followed by hybridization of circle 4.2 (A1) and circle 1 (A2). Polymerase extends the primers using the circles as templates. Cy5-labeled oligonucleotides (D1), complementary to the extended DNA from primer 4.2, and Cy3-labeled oligonucleotides (D2), complementary to the extended DNA from primer 1, are hybridized to the extended DNA strands, producing signal amplification in two colors.