Protein – Protein
Protein – DNA
Protein – Small molecule or fragment.
Protein – Carbohydrate
Protein – Lipid or Membrane / Liposome interactions
Protein - RNAIn a kinetic experiment it is possible to determine the association rate, dissociation rate and the dissociation constant. Data from a monoclonal antibody to a peptide is shown in picture 2. The antibody is immobilized on the chip and different concentrations of the peptide are injected. The association and dissociation rates are determined by global fitting (shown as a red line). Global fitting fits association and dissociation rates to you data at all the different concentrations at the same times, this gives a much more accurate and reliable rate constants and dissociation constant.
And any combination of these. Basically most relevant biological interactions are measurable. However, bacteria and cells are problematic (Virus seems to work better) and should be avoided with this system since they tend to clog the thin capillaries.
Proteon is a SPR based biosensor from Bio-rad. It main feature is it is capable of doing six injections simultaneously over six different flow cells. This makes the system a higher through put then biacore 3000. The proteon has wider flowcells which makes it more robust and less sensitive for clogging. We have successfully analyzed bacteria binding to adhesions with proteon. The Sensitivity is less than for Biacore 3000 but it is still possible to measure protein small molecule interactions.
Auto-ITC is a fully automated iso thermal caliometry from GE. It measure the change in heat when two molecules interact. From the data you can determine the dissociation constant, enthalpy and entropy and stoichiometry. The system can analyze around 20 samples per day. The most common applications are protein – protein and protein small molecule interactions but it has the ability to measure any type of interaction. It requires more material then SPR but has the advantage it is in a solution based method and does not require any immobilization.
LigandTracer® Green – an instrument for real-time quantification of binding of fluorescently labeled biomolecules or bacterial cells to immobilized cells or receptors.
LigandTracer® Green offers a simple and accurate method for detection and quantification of biomolecular/cells interactions in real‐time using fluorescently labeled biomolecules. Measurements of e.g. on‐off rate, affinity or retention can be made using blue (~488nm) and green (~535nm) fluorophores, e.g. FITC, Alexa Fluor® 488, as labels. A detector for Yellow (590nm) - Red (632nm) for Rhodamine Red and similar fluorophores is also available.