| 摘要 |
<p>PURPOSE: To produce a useful substance in a large quantity by inserting a gene DNA having recognition sequences against a restriction enzyme A at both the ends into a cloning vector and transferring the gene held on the cloning vector into an expression vector in a simple and sure manner. CONSTITUTION: A cloning vector and an expression vector having an identical kind of drug resistance genes are used. A gene DNA having a recognition sequence against a restriction enzyme A at each of both the ends is inserted into the cloning vector to combine, and a position of the drug-resistant gene is cleaved. At least an active region of the drug-resistant gene is decomposed to be removed. Both the ends of the cloning vector are made blunt. Subsequently, the cloning vector is fragmented with the restriction enzyme A, and the fragments are inserted into the expression vector. The transformed somatic cells, which these expression vectors are introduced to, are screened by using the drug resistance as an indicator. This enables the expression even of a miner PCR product in a large quantity.</p> |
