Voltage-programming-based capillary gel electrophoresis for the fast detection of angiotensin-converting enzyme insertion/deletion polymorphism with high sensitivity.

A voltage-programming-based capillary gel electrophoresis method with a laser-induced fluorescence detector was developed for the fast and highly sensitive detection of DNA molecules related to angiotensin-converting enzyme insertion/deletion polymorphism, which has been reported to influence predisposition to various diseases such as cardiovascular disease, high blood pressure, myocardial infarction, and Alzheimer's disease. Various voltage programs were investigated for fast detection of specific DNA molecules of angiotensin-converting enzyme insertion/deletion polymorphism as a function of migration time and separation efficiency to establish the effect of voltage strength to resolution. Finally, the amplified products of the angiotensin-converting enzyme insertion/deletion polymorphism (190 and 490 bp DNA) were analyzed in 3.2 min without losing resolution under optimum voltage programming conditions, which were at least 75 times faster than conventional slab gel electrophoresis. In addition, the capillary gel electrophoresis method also successfully applied to the analysis of real human blood samples, although no polymorphism genes were detected by slab gel electrophoresis. Consequently, the developed voltage-programming capillary gel electrophoresis method with laser-induced fluorescence detection is an effective, rapid analysis technique for highly sensitive detection of disease-related specific DNA molecules.

A Pixel Circuit for Compensating Electrical Characteristics Variation and OLED Degradation.

In recent years, the active-matrix organic light-emitting diode (AMOLED) displays have been greatly required. A voltage compensation pixel circuit based on an amorphous indium gallium zinc oxide thin-film transistor is presented for AMOLED displays. The circuit is composed of five transistors-two capacitors (5T2C) in combination with an OLED. In the circuit, the threshold voltages of both the transistor and the OLED are extracted simultaneously in the threshold voltage extraction stage, and the mobility-related discharge voltage is generated in the data input stage. The circuit not only can compensate the electrical characteristics variation, i.e., the threshold voltage variation and mobility variation, but also can compensate the OLED degradation. Furthermore, the circuit can prevent the OLED flicker, and can achieve the wide data voltage range. The circuit simulation results show that the OLED current error rates (CERs) are lower than 3.89% when the transistor's threshold voltage variation is ±0.5V, lower than 3.49% when the mobility variation is ±30%.

Fast high-throughput screening of glutathione S-transferase polymorphism by voltage programming-based multi-channel microchip electrophoresis.

Glutathione S-transferase (GST) polymorphism (M1 = 215 bp and T1 = 480 bp) can cause liver damage and increase the risk of cancer. In this study, voltage programming (VP)-based microchip electrophoresis (ME) with a laser-induced fluorescence (LIF) detector was developed to detect specific sizes of DNA fragments. The optimum conditions for a single-channel microchip were as follows: 4 kV for 0-9.5 s, 1.5 kV for 9.5-15.5 s, and 4 kV for 15.5-30 s. Next, these conditions were applied to another microchip that was constructed with many channels making possible simultaneous parallel detection. Finally, GST genes extracted from human blood were amplified by polymerase chain reaction (PCR) and were introduced into the multi-channel microchip. Target DNA molecules amplified by only 10 PCR cycles could be detected by the VP-based multi-channel ME method, but not by slab gel electrophoresis (SGE). In addition, the migration time for ME was <15 s, which was 700 times faster than conventional SGE. The developed VP-based multi-channel ME method with LIF detection was demonstrated to be an effective, rapid analysis technique for highly sensitive and high-throughput screening of GST genes.