Mix-n-Stain™ Total Protein Prestain Kits are designed for rapid and sensitive protein quantitation on SDS-PAGE gels and western blot (WB) membranes via protein labeling with near-infrared CF® dyes. The labeling can detect as little as 1 ng protein, and shows superior linearity for western normalization compared to housekeeping proteins. The kits allow easy and fast labeling of purified proteins or cell lysates with near-infrared CF® dyes. To label protein samples with the kits, one simply needs to mix the dye and the buffer with the protein solution, follow by a brief incubation before preparing samples for SDS-PAGE. After electrophoresis, the bands can be visualized using a fluorescent gel scanner, eliminating the need for gel staining. Labeled proteins on SDS-PAGE gels also can be transferred to membranes and detected by western blotting. No purification is needed after labeling, because the excess CF® dye runs to the bottom of the gel and does not interfere with protein imaging. After protein transfer, the excess dye will be washed off the membrane, leaving only the labeled proteins. For SDS-PAGE gel prestaining, the kits allow detection of low concentration proteins down to 1 ng with minimal background. The dyes do not cause any visible change to the shape or mobility of the bands compared to unlabeled proteins visualized by post-staining methods. For western blotting, the kits demonstrate outstanding linearity for quantitation of total protein over a wide dynamic range, outperforming the traditional normalization method based on housekeeping proteins. The prestaining does not affect protein detection by antibodies. Typhoon is a trademark and Cy dye is a registered trademark of GE Healthcare; Odyssey is a registered trademark of LI-COR Biosciences.
Highly sensitive protein quantitation on PAGE gels or western membranes Easily label proteins or cell lysates with near-IR CF® dyes before SDS-PAGE No purification after labeling Detect as little as 1 ng protein Superior linearity for western normalization compared to housekeeping proteins CF®680T (Ex/Em 681/698 nm) for Typhoon™ Cy®5 or IR Short filter or Odyssey® 700 channel CF®770T (Ex/Em 764/787 nm) for Typhoon™ IR Long filter or Odyssey® 800 channel