The invention relates to a method for producing a membrane ring or test strip ring for a diagnostic test device, wherein a) an elongated strip (26) is divided into segments (20) by cuts (24) running transverse to the longitudinal axis of the strip, b) wherein the cuts (24) are made only as far as a residual width of the strip (26), so that a material bridge (38) remains intact between segments (20) adjacent at the cuts (24); c) the strip (26) is closed by joining the ends thereof together into a ring (22), wherein the cut edges of the cut (24) running toward the material bridges (38) each enclose an acute angle (alpha); d) the ring (22) is placed in a support structure (12) as a membrane ring or test strip ring for the test device.