Technical Improvements in Quantitative In Vitro Microdialysis Sampling of Carbohydrates

Abstract

The use of quantitative in vitro microdialysis has far-reaching applications to monitor a wide variety of bioprocesses without complex sample preparation procedures. On-line in vitro microdialysis sampling followed by high performance anion exchange chromatography and pulsed electrochemical detection was employed to monitor carbohydrate enzyme kinetics. A key improvement to the microdialysis perfusate delivery system is reported to enhance reproducibility, accuracy, and recovery. A computer-programmable pump designed for precision fluid delivery, with flow rates in the nano- and microliter per minute range that did not require perfusate reloading, was used in place of the commonly used syringe pump. Peak-to-peak noise levels were reduced by three orders of magnitude and recoveries at low flow rates (less than 1 µL/min) were greater than 90% for glucose. In addition, accurate and reproducible delivery allows for on-line dilution for flow rates across two orders of magnitude.

Keywords:

• carbohydrate
• microdialysis