Recombinant protein is the result from the expression of recombinant DNA within living cells. When recombinant DNA encoding a protein is introduced into a host organism, the recombinant protein is not necessarily produced.Expression of foreign proteins requires the use of specialized expression vectors and often necessitates significant restructure by foreign coding sequence.Recombinant DNA differs from genetic recombination in that the former results from artificial methods in the test tube, while the latter is a normal biological process that results in the remixing of existing DNA sequences in essentially all organisms.