Monitoring of glucose in cell culture by glucose binding protein (GBP) combined with ultraslow microdialysis

BIOT 271

Xudong Ge, xge1@umbc.edu1, Michael A. Hanson, m.hanson@umbc.edu2, Govind Rao, grao@umbc.edu3, and Leah Tolosa3. (1) Center for Advanced Sensor Technology, Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County, 5200 Westland Blvd., Baltimore, MD 21227, (2) Center for Advanced Sensor Technology, Department of Chemical and Biochemical Engineering, University of Maryland, Baltimore County, TRC 227, 1000 Hilltop Circle, Baltimore, MD 21250, (3) Center for Advanced Sensor Technology, Department of Chemical and Biochemical Engineering, University of Maryland at Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250
Glucose is the major carbon and energy source in cellular metabolism. The lack of glucose in the medium will limit cell growth and product yield in bioprocesses while excessive glucose can also be detrimental leading to lactate formation via the glycolytic pathway. Here we describe a GBP-based assay combined with ultraslow microdialysis for glucose monitoring in cell culture. GBP is one of the soluble binding proteins found in the periplasmic space of gram-negative bacteria. It can be used for glucose monitoring by attaching a polarity sensitive probe to a site on the protein that is allosterically responsive to glucose binding. The microinjector used for sampling is connected through plastic tubing to a dialysis probe immersed in the medium. The glucose concentration in the dialysate depends on the glucose concentration in the medium, the flowrate of the perfusion buffer, and temperature. Depending on the desired dialysis efficiency, the flowrate can be adjusted stepwisely from 0.1 μL/min to 100 μL/min to accommodate the sensitivity of the glucose assay, which is in micromolar range.
 

Poster Session
5:30 PM-7:30 PM, Wednesday, August 22, 2007 BCEC -- Exhibit Hall - B2, Poster

Division of Biochemical Technology

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007