A new design for a liquid scintillation counter for micro samples using a flat-bed geometry

Abstract

A new design for a liquid scintillation counter based on a flat-bed geometry is described. Micro-samples are dried or filtered onto transfer membranes or glass fibre filters in a 6 × 16 matrix, compatible with 96-well micro-titration plate filtration assays of labelled cells. A prototype counter without lead shielding had low background countrates (2–3 cpm for ³H) giving a figure of merit of 1325 (and 1292 for ¹⁴C). Only 5–15 ml of scintillant/96 samples are required and thus the volume of radioactive waste is low.