Method for gene expression

A method for gene expression in a cell-free transcription/translation system, the reaction solution in a reaction vessel containing all components necessary for transcription/translation mechanism, amino acids, nucleotides, metabolic components which provide energy and which are necessary for the synthesis,

• wherein proteins arising during transcription/translation are immobilized on a matrix such that
• the reaction solution is conducted over the matrix disposed outside the reaction vessel and in a separate immobilization vessel passed by the reaction solution,
• wherein the concentration of the proteins is determined before and behind the matrix with respect to the direction of flow of the reaction solution through the matrix.