Among the biochemical methods of genetic engineering, the Western Blot detects:

Southern blotting is used to identify and isolate a specific DNA sequence and can also quantitatively determine the number of times a specific sequence occurs in a paicular cell type. Western blotting is a biochemical technique, adapted from a similar technique for DNA of Southern blotting, for detection and identification of specific proteins. Nohern blotting allows researchers to determine the level of production (and, therefore, control of expression) of a paicular mRNA by quantitative determination of the relative amount of that paicular mRNA relative to total mRNA. A method was also developed to detect post-translational modifications to proteins (eastern blotting). Ref: Weil P. (2011). Chapter 39. Molecular Genetics, Recombinant DNA, & Genomic Technology. In D.A. Bender, K.M. Botham, P.A. Weil, P.J. Kennelly, R.K. Murray, V.W. Rodwell (Eds), Harper's Illustrated Biochemistry, 29e.