cDNA genes are a locus (or region) of DNA for functional transcript RNA or protein. An ELISA is used to detect the expressed protein in biological fluids, serum, saliva.Peptides short amino acid chains or epitopes or blocking antagonists. The shortest peptides are dipeptides, consisting of 2 amino acids joined by a single peptide bond, followed by tripeptides, tetra peptides, ... till polypeptides that are long, continuous, and unbranched synthetic peptide chains. These biological oligomers and polymers can be Solid-phase peptide synthesis (SPPS), or in continue produced for custom peptide synthesis projects. The High-efficiency solid phase peptide synthesis (HE-SPPS) is give very low production costs.
Human proteins, cDNA and human recombinants are used in human reactive ELISA kits and to produce anti-human mono and polyclonal antibodies. Modern humans (Homo sapiens, primarily ssp. Homo sapiens sapiens). Depending on the epitopes used human ELISA kits can be cross reactive to many other species. Mainly analyzed are human serum, plasma, urine, saliva, human cell culture supernatants and biological samples.