On the Possibility of Real-Time Monitoring of Glucose in Cell Culture by Microdialysis Using a Fluorescent Glucose Binding Protein Sensor
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- 作者：Xudong Ge ; Govind Rao ; Leah Tolosa
- 刊名：Biotechnology Progress
- 出版年：2008
- 出版时间：June 2008
- 年：2008
- 卷：24
- 期：3
- 页码：691 - 697
- 全文大小：176K
- 年卷期：v.24,no.3(June 2008)
- ISSN：1520-6033
文摘
Although glucose sensors with millimolar sensitivity are still the norm, there is now a developinginterest in glucose sensors with micromolar sensitivity for applications in minimally invasivesampling techniques such as fast microdialysis and extraction of interstitial fluid by iontophoresisand laser poration. In this regard, the glucose binding protein (GBP) with a binding constant forglucose in the micromolar range is of particular relevance. GBP is one of the soluble bindingproteins found in the periplasmic space of Gram-negative bacteria. Because of its hinge-liketertiary structure, glucose binding induces a large conformational change, which can be usedfor glucose sensing by attaching a polarity sensitive fluorescent probe to a site on the proteinthat is allosterically responsive to glucose binding. Correspondingly, the resulting optical biosensorhas micromolar sensitivity to glucose. Because binding is reversible, the biosensor is reusableand can be stored at 4 
ges/entities/deg.gif">C for 6 months without losing its sensitivity. In this paper, we show thefeasibility of using the GBP biosensor to monitor glucose in microdialysis. The effect of perfusionrate, bulk glucose concentration and temperature on microdialysis efficiency was determined.Additionally, the glucose concentrations in mammalian cell culture were monitored to demonstratethe applicability of this sensor in complex and dynamic processes over a period of time. As thesensor is sensitive to micromolar glucose, high dialysis efficiency is not required when the bulkglucose concentration is within the millimolar physiological range. Thus, a perfusion rate of 10ges/entities/mgr.gif">L/min or faster can be used, resulting in delay times of 1 min or less.