Stability of biological characteristics of recombinant Escherichia coli expressing human thioredoxin

Abstract:

[Objective] This study was to detect the stability of biological characteristics of recombinant E. coli BL21/pET-22b(+)-rhTrx expressing human thioredoxin. [Methods] Recombinant E. coli BL21/pET-22b(+)-rhTrx was subcultured for 50 passages, and subjected to transmission electron microscopy, Gram staining and biochemical examination as well as test for expression level of target protein and property of plasmid every 10 passages. [Results] The results of restriction analysis and sequencing of various passages were in agreement. All the expression levels of target protein in recombinant E. coli BL21/pET-22b(+)-rhTrx of passages 0, 10, 20, 30, 40 and 50 passages were about 20%, which showed no significant difference. All the passages were negative in Gram staining and showed typical characteristics of E. coli under transmission electron microscope and in biochemical examination. [Conclusion] The recombinant E. coli BL21/pET-22b(+)-rhTrx showed stable biological characteristics and might be used as a bacterial seed for production.