Non-radioactive detection of proteins synthesized in vitro. Using these systems, biotinylated lysine residues are incorporated into nascent proteins during translation, eliminating the need for labeling with [35S]methionine or other radioactive amino acids. Biotinylated lysine is added to the translation reaction as a precharged ε-labeled biotinylated lysine-tRNA complex (Transcend™ tRNA) rather than as a free amino acid. After SDS-PAGE and electroblotting, biotinylated proteins can be visualized by binding either Streptavidin-Alkaline Phosphatase (Streptavidin-AP) or Streptavidin-Horseradish Peroxidase (Streptavidin-HRP), followed by colorimetric detection. Typically, these systems enable you to detect 0.5–5ng of protein in 3–4 hours after gel electrophoresis. This sensitivity is equivalent to that achieved with [35S]methionine incorporation and autoradiographic detection 6–12 hours after gel electrophoresis.
For more information, see the Protocols & Applications Guide.