LabLogic radio-HPLC detector valuable for PET research""
10 September 2008
The University of Manchester's Wolfson Molecular Imaging Centre in the UK is using a Dual BGO radio-HPLC detector from LabLogic Systems to detect low-level radionuclides for its research into PET methodologies.
Focused on research in the fields of oncology, neurology and psychiatry, the Centre has extensive facilities for cGMP synthesis of tracers, including 15O water and 11C-labelled PK11195, methionine, MDL100907, DASB and verapamil.
"In some cases we follow the in-growth of radiometabolites in human plasma after administration of PET tracers," explains the Centre's Dr Adam McMahon. "This is a challenging task that requires a combination of sample preparation methods, HPLC and sensitive radiodetection."
"We use the Dual BGO detector on one of our radiochromatographs as a tool for method development. We have found it to be sensitive and effectively free from background noise without shielding, and a valuable tool for the development of our radiometabolite protocols."
The instrument interfaces with LabLogic's Laura radiochromatography data collection and analysis software package, which offers the half-life correction functionality that is imperative when working with PET radionuclides.
The Dual BGO system has two 1-inch diameter x 1.5-inch thick BGO crystals mounted on 1.5-inch photomultiplier tubes (PMT), amplifier electronics for each BGO/PMT detector unit, and a coincidence circuit that produces a count only when events are detected in each unit within a 1 microsecond window.
PET radionuclides decay by positron emission, and the positrons combine with electrons and annihilate with two 511 keV gammas emitted in opposite directions. If the emission comes from the volume between the two detector units, there is a high probability that a coincidence event has been detected. For events which originate outside this region, or for other gammas from normal laboratory background, there is no coincidence event.
The result is a very low background system capable of detecting low-level PET labelled metabolites.