Fig. 1From: pXST, a novel vector for TA cloning and blunt-end cloningDiagrammatic presentation of the pXST construction. XcmI-ccdB-XcmI cassette is derived from the pDNOR221 vector. The recognition sites for XcmI and SmaI were indicated as italic. The lethal gene ccdB was marked in red colorBack to article page