- In order to enhance cell culture growth in bioreactors, biosensors such as those used for glucose detection must be developed that are capable of monitoring cell culture processes continuously and preferably noninvasively. The development of a unique noninvasive, optically based polarimetric glucose sensor is reported. The data were collected using a highly sensitive, lab-built polarimeter with digital feedback and a red laser diode source. A range of glucose concentrations was evaluated using both glucose-doped double-distilled water and a bovine serum-based medium. The serum-based medium is the nutritional environment in which the cell cultures are grown. Both media were examined across two glucose concentration ranges - a lower range of 100 mg/dl in 10-mg/dl increments and a higher range up to 600 mg/dl in 50-mg/dl increments. The linear regression in all experiments yielded standard errors of prediction of less than 8.5 mg/dl across both ranges. 1997 Society of Photo-Optical Instrumentation Engineers.