Extremely small amounts of Tween 20 or Triton X-100 are added to a mixture of non-fat dry milk and water to create a common blocking solution used in this technique.
The fluorescent dye Sypro Ruby can be used in place of the anionic dye Ponceau S for increased sensitivity in this technique. Extremely small amounts of Tween 20 or Triton X-100 are added to a mixture of non-fat dry milk and water to create a common blocking solution used in this technique. Two commonly-used reporter enzymes in this technique are alkaline phosphatase and (*) horseradish peroxidase. Those enzymes are typically added alongside a secondary antibody before washing this technique's substrate in a buffer solution. Visualization of this technique occurs following the transfer of an SDS-PAGE gel onto a nitrocellulose membrane. For 10 points, name this technique for identifying proteins named for a cardinal direction. 
The fluorescent dye Sypro Ruby can be used in place of the anionic dye Ponceau S for increased sensitivity in this technique.
Western blot 