[Multicenter pilot studies on the determination of steroid hormone receptors].

Corresponding the international tendency two trials have been performed in GDR to compare results of hormone receptor determinations with prepared probes by several laboratories. As probes we used lyophilized calf uterus. Methods applied for receptor determinations based on dextran charcoal technique, but allowed modalities developed in the various laboratories. In consequence of extensive scattering of results got during the first trial an additional investigation basing on a standard procedure was performed in the second trial. Using this standard procedure better corresponding results could be found in comparison to investigations following the laboratory modalities. Consequently application of a standardized technique in all laboratories should be demanded. Final aim of these efforts is to obtain a reliable semiquantitative classification of low, medium and high receptor contents in the tissue probes investigated.