Fabrication of the PDMS microchip for serially diluting sample with buffer

We developed a polymer polydimethylsiloxane (PDMS) based microfluidic device that dilutes biological samples with buffer solutions with serially increasing diluted sample concentrations. The device showed the relatively high accuracy in terms of dilution ratios along with the fact that it was faster and easier to operate. With two simple disposable plastic syringes, the plastic microfluidic chip completes ordinary sample dilution sequences faster and more precisely than the conventional manual pipette process in biological or chemical laboratory. The serially diluting mechanism of the microchip is simply that the number of microchannels with the same flow rate determines the total amount of flow into the wells. The soft lithography fabricated the microchannels of tetragonal section length of 50 mum of each side of the microfluidic chip.