Note in the transcription process from double stranded DNA, it is possible to transcribe either strands of DNA and hence in reality there are 6 reading frames corresponding to every single strand sequence. The location of a gene in a chromosome is designated as it locus. This map does not provide the actual distance in terms of base pairs. This map provides the actual distance in base pairs between genes or markers. The cut is made between G and A. Note that the the restriction sequence is a palindromic sequence.
Popular vectors are plasmids, cosmids, phages, BACs and YACs.
Maximum of 15kbp can be cloned as inserts into a plasmid. These are called cosmids. Another way of producing copies of DNA is using the polymerase chain reaction. Each repetition doubles the number of DNA molecules. DNA or RNA molecules are charged in aqueous solution and move to a definite direction by the action of an electric field.