ABSTRACT
Some sequences, known as promoters, are able to bind to transcription factors in the upstream portion of transcription units of the DNA and give rise to RNA via transcription. The most important of these is RNA polymerase which reads the antisense strand of the gene and produces a sense-encoding RNA copy using nucleotide triphosphates of the bases adenine, uracil, cytosine and guanine. Capping is ultimately necessary for recognition of the mRNA by the small ribosomal subunit, to enable translation, whereas polyadenylation stabilizes the transcript in the cytoplasm. The clones which have been identified and isolated can then be sequenced and the amino acid sequence of the encoded protein deduced. This DNA can be further manipulated and constructs prepared from which functional proteins can be isolated and characterized to show that the gene of interest has indeed been isolated. The most effective method for the isolation of RNA from a range of tissues uses guanidinium thiocyanate and acidic phenol.
