The plasmids pBR322 and RSF1010, extracted from E.coli HB802 and E. coli C600 respectively were treated with restrictive endonuclease EcoRI and ligated with T4 DNA ligase. C600 strains were then transformed with the hybrid plasmid, and thus 253 transformants were obtained.The figures of gel elctrophoresis and electromicrograph proved that PSMM1 was a pBR322 : RSF1010 composite hybrid.In E. coli C600 PSMM1 obtained resistance against AP, Tc and Sm.The orientation of pBR322 and RSF1010 in hybrid PSMM1 and the failure of introduction of this hybrid into P.Putida AC10 were discussed

The recombinant plasmids containing IFN-?B gene fragments were constructed by ligating IFN gene fragment trimmed by Bal-31 exonclease and vector pUR222 digested by HincⅡ . In some of the recombinant plasmids ?B-IFN gene was able to be expressed under the control of lac. promoter of pUR222. Over 700 transformants were screened by cylopathogenic inhibition assay in microplate. Fifteen transformants showed antiviral activity,and one of them, pSM2317 reached 1?108 U/L.

OBJECTIVE:To explore the optimal steaming time of Carapax trionycis during cleansing period,and to optimize and improve production technology of Carapax trionycis recorded by current Chinese Pharmacopoeia. METHODS:The mechanical processing replaced the artificial processing method in Chinese Pharmacopoeia. The content of protein and the appearance of Cara-pax trionycis were investigated after steaming for 30,60,90,120,180,240 min during cleansing period. The extract,decoction, ash content,appearance and property of Carapax trionycis decoction piece processed with vinegar were also investigated after cleansed Carapax trionycis decoction piece was processed by sand scalding and vinegar quenching method. RESULTS:The differ-ent steaming time obtained different quality of cleansed Carapax trionycis decoction piece and Carapax trionycis decoction piece pro-cessed with vinegar. Compared with decoction piece steamed for other duration,when the steaming time was 90 min,the content of protein in cleansed Carapax trionycis decoction piece was higher(31.16%),and its appearance was up to the requirement. Cara-pax trionycis decoction piece processed with vinegar had higher contents of extract and decoction(9.13%,11.39%)and lower con-tent of ash(66.29%),and its appearance was up to the requirement. CONCLUSIONS:Different steaming time have certain effect on the quality of cleansed Carapax trionycis and Carapax trionycis processed with vinegar,the optimal steaming time of Carapax tri-onycis is about 90 min during cleansing. The mechanical processing method maybe replace the artificial processing on Carapax tri-onycis for improving its production efficiency.

An recombinant vector pCSV-EPO for expression of EPO cDNA in mammalian cells was constructed by the techniques of gene recombinant, PCR amplification and region-specific mutagenesis. The pCSV-EPO was introduced into COS7 cells by DEAE-dextran-mediated transfection. The expression of the EPO was demonstrated by EPO-ELISA assay. At 48h post transfection, the EPO level was 25ng/ml and 72 h was 17ng/ml.