Abstract: The invention relates to a method for determining biochemical parameters of a body fluid, wherein a sample of said body fluid in the form of a droplet is transported through a channel of a microfluidic system using a carrier liquid, mixed with a reagent thus initiating a chemical reaction between the sample and the reagent, and the result of the chemical reaction is measured, preferably with a spectrophotometer, whereby the said biochemical parameters of the body fluid are determined, characterised in that the material used for fabrication of the microfluidic system and the said carrier liquid is pair of Teflon and Fluorinert HFE-7100.