Label-Free Analysis of Protein ArraysSPRimager®II Analysis of Arrays Prepared on a Continuous Flow Microspotter Introduction The SPRimager®II is a label-free array detection system designed for rigorous, quantitative analysis of molecular interactions. Arrays for analysis on GWC’s SPRimager®II system are typically fabricated by spotting sub-microliter volumes of ~0.1 – 1 mg/mL probe solutions onto array substrates (chips). However, when only dilute probe solutions are available, direct spotting of small volumes may not deposit a sufficient concentration of probe molecules on the chip to detect analytes in subsequent analyses. Using Continous Flow Microspotting (CFM), arrays are fabricated by continuously flowing probe solutions over the array substrate. During CFM, greater densities of probe molecules can be deposited on the chip than can be achieved by traditional spotting methods with dilute probe solutions. CFM is therefore particularly well suited for experiments that involve immobilizing molecules out of a low concentration solution. This note details use of GWC’s SPRimager®II in conjunction with the Wasatch CFM system to fabricate and analyze protein arrays printed from low concentration probe solutions. The results show that CFM printing using as little as 2μg/mL protein solution generates protein arrays suitable for analysis on GWC’s SPRimager®II system, and suggest that much lower probe concentrations may be successfully used in some cases. Click here to view this entire PDF.
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