A method of rapid prototyping of a microfluidic polymer chip with submillimeter cross-sectional dimensions of working channels is considered. A fundamentally important condition was the choice of an inexpensive method for creating a microchip in a research laboratory at the stage of checking its operability and pre-selecting the geometry of both the device as a whole and its main functional elements. The paper discusses the method of “xurography”, which consists in forming the chip structure in thin films on a cutting plotter and then connecting them to each other using adhesive layers. As a result, a workable configuration of the microfluidic device was created, which ensures mixing of the two-component sample and transfer of the reaction product to the detection zone. For the model object, estimates of additional dilution of the concentration peak were obtained based on the specified characteristics in the approximation of the method of moments and an increase in the mixing efficiency of components using a serpentine microchannel was confirmed. At the Institute for Analytical Instrumentation of the Russian Academy of Sciences, the xurography method is used for operational prototyping of microfluidic devices with working channels over 300 μm wide and 100 μm deep. The abstract should summarize the contents of the paper in short terms, i.e. 150–250 words; justified between the margins and using the font/size specified below.