Conceptual Design of a Fluid Handling System with Dosing and Mixing for PCR Applications

Abstract

Typically, samples for PCR instruments are prepared manually by trained laboratory personnel, which in this case refers to the sample preparation, the dispensing of a master mix and a biological sample with subsequent mixing. To reduce the workload, there are approaches towards fully automated PCR systems, but in most cases only proprietary thermal cyclers can be used. Other approaches involve a similarly complex robotic solution. In this work, the spectrum was extended by a method that can be integrated into the workflow of existing PCR protocols. For this purpose, a user-friendly solution using a microfluidic chip was developed. For the sample preparation different mixing concepts were selected as well as a concept for aliquoting. Optimization and evaluation were assisted by utilization of simulations to study system behavior. The systems consisting of a mixer and a flow splitter were manufactured by milling. Subsequently, the mixing and aliquoting capability of the system could be investigated in the laboratory assembly. The testing of this prototype showed moderate results which are attributed to the accuracy of the laboratory assembly.