aBatchSystem Using Wheat Germ Extract

modified and unnatural amino acids into protein are possible.t) However, the relatively small amount of product due to early stopping of the translational reaction has been the primary bottleneck for its application. To overcome this problcm, Spirin and co-workers developed a continuous-fiow cell-free translation system, called the CFCF system, in 1988.2) In this system, the protein synthesis is maintained at a constant rate for more than 20 hours. Their results have been recently confirmed by other laboratories,3-6) but it is still unknown why such a prolonged synthesis period is achieved in the CFCF systern but not in the batch system. In our previous paper,7) a high translation rate ofdihydrofolate