The invention is based on a method for performing a biochemical analysis, especially in outer space, wherein at least one analyte in a sample (12a-e) is determined qualitatively and/or quantitatively by means of selective binding of an analyte-specific pair composed of a binding substance (14a-e, 16b-e) and a detection substance (20a-e, 22b-e) to the analyte and by labeling by a labeling substance, and wherein the sample, the binding substance (14a-e, 16b-e), the detection substance (20a-e, 22b-e) and the labeling substance are mixed in a reaction vessel (26a-2) in one method step. It is proposed that the mixing be brought about by means of mixing bodies (18a; 18d; 18e, 30b-c, 32b-c).