Team:USTC CHINA/Project/Results
From 2013.igem.org
Stage one:basal experiments
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As the construction and concentration of recombinant plasmid rely heavily on E.coli system in current molecule experiment protocols of Bacillus subtilis, Bacillus subtilis acts only as the secretory expression vector. Therefore, to verify the practicality of our locus and the transdermal function of recombinant transdermal protein on top of its original functions, we conducted basic experiments on E.coli to verify above assumptions.
The following figue shows the stages of our basal experiments.
① E.coli BL21 proved that the standard transdermal locus does work with GFP.
Using GFP to prove the validity of a newly designed circuit is a classical way to verify the expressing of this circuit. As expressions in E.coli involve neither secretory nor sequential problems, we hoped to verify the practicality of our locus by the expression of TD1-GFP. Thus we selected pET22b,which is a common recombinant vector for plasmid construction, as our recombinant vector and E.coli BL21 as engineered bacteria . We fused sequence TD1-GFP with T7 promoter from pET22b downstream and succeeded in expressing fusion protein TD1-GFP, induced by IPTG.
The molecule weight and key marker data of fusion protein TD1-GFP
② The expression of recombinant antigen and adjuvant in E.coli BL21.
The practicality of our locus afforded by TD1-GFP enabled our to express recombinant antigen TD1-HBsAg and recombinant adjuvant TD1-LTB successfully. So far our basic molecule experiments have ended with perfection.
③ The antigenicity of the TD1-antigen(fusion protein) strongly proved our theoretical basis.
Verify the antigenicity of TD1-HBsAg with ELISA
④ Verify that TD1-HBsAg is able to pass across the skin and keep its antigenicity by transdermal experiments.
To prove that TD1-HBsAg is able to pass across the skin and keep its antigenicity,为we utilized a special device in the picture, whose upper tube and lower tube can be separated by fresh skin peeled from mice, and all we were required to do was fastening the device, adding protein solution to the upper tube and extracting appropriate volume of liquid from the physiological saline in the lower tube to check the concentration of TD1-HBsAg which had crossed the skin during diverse periods.
The devices below are the facilities for trransdemal experiments.
Check the concentration of TD1-HBsAg in the liquid under the skin during diverse periods with ELISA