Response of Plastic Scintillators to Low-energy Photon

Question: Define the mechanism that is used to encounter if there is presence of any quencher while analysing. How does it measure the radiation having different radiation intensities? Answer: Scintillation was discovered at university of California by Samuel Curran in 1944.Scintillation is the instrument commonly used to measure excitation effect on radiation on scintillation object (Peralta and Rego, 2014). To measure the membrane and ligand binding through scintillation there is specific steps to be followed. Cells which have to be analysed is homogenized with buffer (50 mM Tris-Cl, 0.32 M sucrose, pH 7.4) and centrifuged at 1500xg at 4oC for 10 minutes. Supernatant was collected and again centrifuged at 13000xg at 4oC for 20 minutes. This process is repeated twice with the homogenisation buffer and pellet is then collected and suspended in the Tris buffer (50 mM Tris-Cl, pH 7.4). In the next step protein ligand is tagged with the radiolabeled compound to form radio ligand and this entire step is called radio ligand binding assay with different nano-molar concentration of [3H] kainite. Non-specific binding was analysed in the presence of 1mM glutamate and further bindin g is done at 4oC at before rapid filtration on GF/C glass filter though cell harvester. Three times washing is done with cold 0.9% saline solution and later this is exposed to scintillating counter with scintillation fluid. As a result of the florescent intensities are measured and at the time through auto analysers connected to an automated computer systems. The binding of membrane to ligand which is radiolabeled automatically reduces the intensity of the radio nucleotide while as unbound ligand does not shows any changes in the detection intensity (Vulluru et al, 2005). References Valluru L, Xu J, Zhu Y, Yan S, Contractor A, Swanson GT. (2005). Ligand binding is a critical requirement for plasma membrane expression of heteromeric kainate receptors. J Biol Chem. 280(7):6085-6093 Peralta L, Rego F. (2014). Response of plastic scintillators to low-energy photons. Phys Med Biol. 59(16):4621-4633.