Sycopel Microdialysis Biosensor

The Sycopel Microdialysis Biosensor combines the techniques of in vivo microdialysis and voltammetry in one integrated device, and has advantages over conventional techniques such as collecting samples at invervals from a microdialysis probe, enabling "real time" measurement of analytes in vivo and greater ease and simplicity of measurements.

The microdialysis biosensor has now demonstrated its potential in measuring small physiological changes involved with learning and memory in vivo³, and with activity in the freely-moving rat^2,17. Its adaptability means it has also been used in both drug evaluation studies and in vitro 'bedside monitoring' of human glycerol levels^1,5.

The microdialysis biosensor centers around a platinum wire set inside a hollow semi-permeable membrane, 230µm in outside diameter. Two 140µm O.D. vitreous silica tubes provide a means for changing the solution inside the probe, giving the microdialysis biosensor its most important feature: the ability to control the micro-environment around the working electrode. This allows enzymes or biologically active molecules to be replaced within minutes, either if they become inactive or if the specificity of the biosensor is to be changed, by using a different enzyme(s). Two extra electrodes, a silver or platinum counter and a silver/silver chloride reference, make up the electrochemical cell and these are both situated in a glass or steel upper compartment, away from the main sensing area. Epoxy is used to seal up the ends and the joins. For concomitant electrophysiological studies, stainless steel recording electrodes are fixed in parallel to the membrane, allowing field potential recording. This can be used both for positioning the microdialysis biosensor and for subsequent activity recording.

Biotech Products, 7462-438 E. Fishers Station Dr., Fishers, IN 46038. Tel: 317-577-4194; Fax: 317-842-9935.