Chemical Assays Include Those Using Biochemical Reagents Like Receptors or Antibodies

Competitive Binding Assays

  1. Isolate/prepare a receptor suspension, or a serum binding protein, or an antibody
  2. Isolate/prepare a small amount of purified hormone
    1. Need to label part of it so it can be visualized
    2. Need pure hormone for standards or references, analytical references.
  3. In each of a series of tubes or wells place the same small amount of label and binder - the binder will be the limiting reagent in this assay
  4. In part of this series of tubes add increasing amounts of unlabeled hormone, one amount in each tube or well starting at zero additional.
  5. In the rest of this series of tubes add a measured volume of the unknowns, one unknown per tube.
  6. Incubate for a period of hours
  7. Separate the hormone bound to the binder from the remaining free hormone by some simple method.
  8. Quantify the amount of label that is bound to the binder; it will be inversely proportional to the amount of unlabeled hormone present since the binder is the limiting reagent - this is a molecular game of musical chairs.