The Direct Detect™ infrared (IR)-based quantification system is an innovative combination of software-controlled instrumentation and EMD Millipore Corporation’s advanced membrane technology, optimized for the detection and quantification of proteins. Biomolecules are applied directly to a card-based hydrophilic polytetrafluoroethylene (PTFE) membrane that is transparent in most of the infrared spectral region. The Direct Detect™ system measures amide bonds in protein chains, accurately quantifying an intrinsic component of every protein without relying on amino acid composition, dye binding properties, or redox potential. Protein concentrations from 0.2 to 5 mg/mL can accurately be determined from a minimal sample volume (2 μL) without bio- or immuno-chemical staining. Sample analysis takes only minutes and in most cases can be performed directly from the buffered or native solution.