FlashPlates and ScintiPlates are popular platforms for running a variety of radiometric screening assays. The Wallac MicroBeta effectively measures both plate types.
MicroBeta detectors comprise two photomultiplier tubes, one above the sample and one below.
FlashPlate is a solid white plate and so MicroBeta measurements are conducted with the upper PM tube only. A comparison is made of MicroBeta with a Packard TopCount, an instrument that employs single PM tube detectors.
ScintiPlate has clear wells so when measured on MicroBeta both upper and lower PM tubes are used. A comparison of MicroBeta performance is made when measuring the same assay with both FlashPlate and ScintiPlate.
A Reverse Transcriptase Assay was performed using a Streptavidin coated FlashPlate (SMP103). In this assay, a biotinylated DNA oligonucleotide acts as a primer for reverse transcriptase (RT) on an RNA template. The signal is generated by incorporation of labeled dTTP into the newly synthesized strand of DNA. Plates were read on both a TopCount and a MicroBeta, and as shown, the MicroBeta effectively reads with only the top PM tubes in use.
To offer as diverse a range of applications as possible, there are a variety of FlashPlate and ScintiPlate coatings and surface treatments available.
The following experiment was devised to show that although using both PM tubes gives ultimate sensitivity, for example, when measuring adherent cells in ScintiPlates, MicroBeta still provides excellent performance with upper tube only counting.
[3H]Biotin was titrated on both Streptavidin coated FlashPlates and ScintiPlates, then bound activity was read on the MicroBeta. The mass bound was determined by the differential between the known mass/DPM