Chips and Qi: microcomponent-based analysis in traditional Chinese medicine.

Over the last 50 years or so Traditional Chinese medicine (TCM) has been subject to intensive basic and clinical research. Although the effectiveness and remarkable safety of TCM have been documented after controlled clinical studies, there are several herbal and animal parts that are toxic or difficult to identify. DNA polymorphism-based assays have recently been developed for the identification of herbal medicines. In this approach, small amounts of DNA are amplified by the polymerase chain reaction and the reactions products are analyzed by gel electrophoresis, sequencing, or hybridization with species-specific probes. With the DNA based identification of TCM materials as an example, chip-based analytical micro devices were developed with the goal of fabricating an integrated device that will enable sample preparation, amplification, and analysis on a single microchip-based device ("lab-on-a-chip"). The application of a silicon-based polymerase chain reaction microreactor and a DNA microarray for the DNA sequence-based identification of toxic medicinal plants is reported here.

Enzyme biosensor for studying therapeutics of Alzheimer's disease.

An electrochemical method for the investigation and comparison of anti-Alzheimer medications that is based on the inhibition of the acetylcholinesterase is presented. The developed amperometric biosensor determines the in-vitro inhibition of the acetylcholinesterase that is co-immobilized with choline oxidase on the working electrode surface of a three-electrode system using gel entrapment. The sensor has been applied to determine the IC50 values of two known and one newly developed Alzheimer remedy. A simultaneous measurement with the photometric standard method shows the applicability of our method for fast drug screening.