FIELD : medicine.SUBSTANCE : group of inventions relates to the field of diagnostic test elements. Said diagnostic test element for determining the analyte comprised in a body fluid sample, said test element comprising at least one test field with at least one detection layer and at least one separation layer located on top of the detection layer for separating erythrocytes and blood pigments from the test sample, moreover, at least one separation layer contains SiO2 in the amount of from 1.0 to 1.6 g/m2 and solid components, including a swelling agent and at least one light-scattering pigment, from a dispersed system saturated with them, obtained by dispersing solid components in a coating composition forming a release layer. Also disclosed is a coating composition capable of forming a release layer on a diagnostic test element, a method of manufacturing a diagnostic test element as well as the use of a diagnostic test element to determine the amount of analyte in a sample of a subject.EFFECT : group of inventions provides for minimizing the differences in the kinetics of diffuse reflection between individual batches of test elements in order to realize a more accurate determination of the amount of an analyte.14 cl, 6 dwg, 2 tbl, 3 ex