Abstract: The invention relates to a method for producing monomeric or dimeric proteins or peptides containing internal or external disulfide bonds, comprising the following steps: a) a cell-free lysate, obtainable from eukaryotic cells, is provided, which contains functional microsomal vesicles, b) a nucleic acid coding the protein or peptide and additionally containing a signal sequence is added to the lysate, c) the lysate with the nucleic acid is held for a given time at a temperature in the range from 20 to 35° C., proteins or peptides formed with the nucleic acid being translocated into the microsomal vesicles, d) the microsomal vesicles are then dissolved, and the proteins or peptides obtained thereby are optionally separated from the lysate.