Local, fast kinetics with PET tracers

3 January 2007

The BioSpace Beta MicroProbe from LabLogic Systems is a unique optical fibre tool for measuring the kinetics of beta-labelled molecules on anaesthetized animals.

Ideal for situations where blood sampling is difficult or impractical, it can be stereotaxically implanted into a blood vessel, organ, tumour or other locus to measure the input function.

Applications include micro-PET (there are no metal parts), behaviour studies and radiotracer development. The MicroProbe can also be used for pharmacokinetics as an alternative to micro-PET.

Up to four probes can be used in an experiment, with one normally used as a reference. A sophisticated software package supplied with the system measures the kinetics of the labelled molecule on-line.

The MicroProbe is compatible with all β+ emitters (11C,18F, 32P) and some energetic β-emitters(131I).

Probes of various lengths are available, with heads in sizes from 250µm to 1µm; the smallest is particularly useful for implantation in blood vessels. Detection of the β disintegrations is measured in a voxel of approximately 1mm.

Probe sensitivity is around 1µCi/ml for 1-second sampling times and femtomol/ml sensitivities are achieved with FDG.

Count rates using a 1 mm diameter probe are 0.55 cps/kBq/ml for 18F and 0.68 cps/kBq/ml for 11C. Background count rate is less than 5 cps.