The promise of antibody and protein microarrays to revolutionize disease diagnostics has failed to live up to the hype primarily due to the problems associated with the printing of the antibodies and/or proteins onto the detection surface. The current standard in printing proteins is pin printing. An alternative to the pin printer is the continuous-flow microspotter (CFM), a protein printer that uses microfluidic flow to print down the proteins. The advantages of the CFM include consistent spot morphology, spot-to-spot uniformity and enhanced surface concentration. Further, the CFM is effective at capturing proteins and antibodies from either dilute or complex (e.g. blood or tissue) samples. In this study, the sensitivity of CFM printing Cy3 and Cy5 fluorescently labeled proteins was determined. Values were obtained at low concentrations tens of ng/mL with low coefficients of variation. Thus, the CFM can effectively print and quantify proteins and antibodies from low concentration and complex buffered samples.