The invention discloses a micro-ring
plasmid synthesis method, and belongs to the technical field of
gene editing. Two pairs of primers are designed, eukaryotic expression plasmids containing selection markers and target fragments are used as templates for PCR amplification to obtain two target fragments, vector plasmids loxp-R6K with specific sequences and the target fragments form recombinant plasmids, the recombinant plasmids contain sequences such as the target fragments,
restriction enzyme cutting sites and R6K replication start sites, and the recombinant plasmids are used for preparing the recombinant plasmids. The recombinant
plasmid is transformed in
Escherichia coli GT115 competent cells, the recombinant
plasmid is verified to have the recombination efficiency of 81% after
bacterial colony PCR amplification, a correctly cloned seed solution is screened and subjected to induced expression to form a bacterial solution containing a screening-
label-free micro-plasmid, the micro-ring plasmid is separated and purified, and the screening-
label-free micro-ring plasmid is obtained. The sequence of the microring plasmid only contains a target fragment and an R6K replication
start site, the accuracy of the size sequence of the microring plasmid in a
bacterial colony cultured and cloned by the microring plasmid is as high as 90%, and the microring plasmid can be efficiently and stably obtained.