RAP uses changes in the frequency and resistance of an oscillating quartz crystal to analyze molecular interactions in real time. This is a label free technique which can provide information on specificity, affinity, and kinetics of moleculular interactions. RAP can also be used to assess structural changes during binding events. Similar in some respects to Surface Plasmon Resonance (SPR), RAP looks at changes in mass on a sensor surface. However, instead of a signal based on refractive index changes as in SPR, RAP technology is based on alterations in the frequency of the oscillating crystal due to binding. Again similar to SPR, one of the binding partners is immobilized on the sensor surface via amine coupling or other chemistries. Self-assembled monolayers (SAMs) can also be used. This is a very new technology (commercially launched 2005) and there is not a lot of information available at present.We will add more information as it becomes available.

Applications:

1. Antigen-antibody complex assembly
2. Hetero protein complex formation
3. Affinity
4. Kinetics

Pros:

1. Lable free
2. Small sample size requirements
3. Can work with synthetic membranes
4. Automated for use with 96 well plates

Cons:

1. New, so untested in many respects.