Quench and Quench Correction

The TopCount Microplate Scintillation and Luminescence Counter is capable of analyzing radiolabeled microplate samples in a wide variety of formats using liquid and solid scintillation counting techniques. Quench is a common interference in scintillation counting which reduces the sample’s apparent activity. In most applications, the level of quench is constant; hence, it need not be considered when comparing the results of a set of samples. However, some experiments produce samples having different amounts of quench. The apparent activities of these samples must be corrected to yield accurate final results. This typically requires a quench indicating parameter and a set of quenched standards. The TopCount incorporates several proven methods of correcting for quench. This paper describes these methods and details several practical protocols for creating quenched standards for use in the TopCount. The paper also describes and presents results of experiments conducted to demonstrate the performance of the TopCount in a variety of quench correction modes.