Protocol for the generation of gene deletions and gene replacements in Escherichia coli O157:H7 using a temperature sensitive allelic exchange system. Technology requires flanking DNA to be cloned into a temperature sensitive vector but the resulting clone allows great flexibility for further modification of the target sequence. It is therefore highly suited to the study of genes in which several rounds of changes are envisaged. - [Read Generation of Gene Deletions and Gene Replacements in Escherichia coli Protocol]
This protocol describes the first step in constructing an array: amplification of the predicted ORFs that are to be included in the array. Gene-specific primers containing vector-specific flanking sequences that facilitate recombinational cloning are used to amplify each ORF. A secondary amplification can be used to extend the length of the homologous vector sequence flanking the ORF. - [Read Genome-Wide Analysis of Protein-Protein Interactions Using a Two-Hybrid Array: Amplification of ORFs]
Inverse PCR is used to amplify and clone unknown DNA that flanks one end of a known DNA sequence and for which no primers are available. The technique involves digestion by a restriction enzyme of a preparation of DNA containing the known sequence and its flanking region. The individual restriction fragments (many thousands in the case of total mammalian genomic DNA) are converted into circles by intramolecular ligation, and the circularized DNA is then used as a template in the PCR. - [Read Inverse PCR Protocol II]
Protocol describes the production of double-stranded RNA (dsRNA) from fragments of cDNAs of candidate genes. The cDNA fragments must be cloned in plasmids with a flanking SP6 and T7 promoter (e.g., pSP72 or pCRII). The plasmid is linearized and sense and antisense RNAs are produced separately by in vitro transcription. After purification, the RNA strands are annealed to yield a dsRNA molecule suitable for RNAi in avian embryos. - [Read Production of dsRNA for RNAi in Avian Embryos Protocol]
Protocol describes the production of double-stranded RNA (dsRNA) from fragments of cDNAs of candidate genes. The cDNA fragments must be cloned in plasmids with a flanking SP6 and T7 promoter (e.g., pSP72 or pCRII). The plasmid is linearized and sense and antisense RNAs are produced separately by in vitro transcription. - [Read Production of dsRNA for RNAi in Avian Embryos Protocol]
In this protocol sequences cloned in standard bacteriophage or plasmid vectors are amplified in PCRs containing primers targeted to flanking vector sequences. The amplified fragments can be analyzed by gel electrophoresis, DNA sequencing, and/or restriction mapping. Many colonies or plaques can be assayed simultaneously. - [Read Rapid Characterization of DNAs Cloned in Prokaryotic Vectors Protocol]