连接酶

• First , the purified pezzis and pcr product of angiostatin are digested by ecor . i and xba i . after purifying the digested products respectively , we ligate these two kinds of dna by t4 dna ligase and construct the recombinant plasmid pezz18 - as . then transform it to the competent e . coli dh5a
  用限制性内切酶ecori与xbai对目的基因as 、表达载体pezz18行双酶切，酶切产物纯化后利用大肠杆菌t _ 4dna连接酶连接构成重组子pezz18 - as ，并转化e . colidh5 ，经氨苄青霉素lb平板初筛后，以菌液pcr和重组子的单、双酶切行进一步鉴定。