Protocol describes the first stages of Southern blotting: digestion of genomic DNA with one or more restriction enzymes, separation of the resulting fragments by electrophoresis through an agarose gel, and transfer of the denatured fragments to a membrane by downward capillary transfer. - [Read Southern Blotting: Capillary Transfer of DNA to Membranes Protocol]
Protocol describes how to prepare double-stranded RNA (dsRNA) for RNA interference in Drosophila by synthesis of individual RNA strands from linearized plasmid templates, followed by annealing of the strands. DsRNA molecules with a length of 500-800 bp seem to be most active. The dsRNA can be made from cDNA or genomic DNA templates, as long as most of the dsRNA corresponds to presumptive exon sequence. - [Read Synthesis of dsRNA for RNAi in Drosophila: Plasmid Template Method Protocol]
DNA microarrays are an ordered arrangement of DNA molecules complementary to genes of interest that are "spotted" by robotic equipment onto a glass slide substrate. The expression of genes in cells can be monitored with microarrays by preparing cDNA from the mRNA of cells of interest and measuring the hybridization to the microarray. This protocol describes the labeling of genomic DNA for use as a probe for hybridization to the cDNA spotted on the array.
The protocol gives general considerations for the design of targeting vectors for transgenic mice. The protocol shares tips in the design of knock-out and knock-in vectors and some of their strategies for producing homologously recombined embryonic stem cells.