The present invention provides a
system and method for rapidly screening sgRNA skeleton (sgRNA
scaffold) active
mutant sequences, belonging to the field of bioengineering technology. The
system comprises a Cas
protein expression vector and an sgRNA skeleton
mutant screening vector; the Cas
protein expression vector comprises the following expression elements: a Cas
protein encoding
gene, a
plasmid replicon, and a first resistance screening tag
expression cassette; the sgRNA skeleton
mutant screening vector comprises the following expression elements: a
replicon, a second resistance screening tag
expression cassette, a third resistance screening tag
expression cassette, a
promoter and a terminator for expressing the sgRNA skeleton sequence. The
system and method can be applied to the screening of sgRNA skeleton elements of the
CRISPR gene editing system. By using this method, a sgRNA skeleton with diverse sequences can be obtained, which can then be applied to fields such as multi-
target gene editing and the construction of a strain
library, thereby expanding the application field and editing efficiency of the
CRISPR gene editing system.