Abstract: A 240-bp DNA fragment coding for the hirudin was chemically and enzymically sythesized. The sequence was derived from the amino acid sequence of the hirudin peptide, which is consistent with the request of yeast gene expression. The sythesis involved preparation of six long oligodeoxyribonucleotides. After annealing, filling by Klenow fragment, three formed fragments were cloned into pBS sequentially, and an intact hirudin gene was obtained. The DNA sequence of the cloned fragment identified by sequencing was the same as the designed sequence of hirudin gene.

Key words: Hirudin, Gene, Sythesis, Cloning