Abstract: Apparatus for diluting, replicating and establishing standards of chemical samples in sample trays, which samples are automatically prepared from specimen material in specimen trays. The apparatus processes a plurality of specimen trays, and prepares samples therefrom, depositing these samples in a pluraity of sample trays. The specimen trays and the sample trays are automatically transported to a station where sample preparation, dilution, and replication is carried out according to predetermined instructions stored in the apparatus. The various trays may be uniquely coded for identification.