Immunogen: Synthetic peptide C-ENPKNQAPPGLYTKTQD from an internal region of human ASS1 (NP_000041.2 ; NP_446464.1). Percent identity by BLAST analysis: Human, Gorilla, Orangutan, Gibbon, Monkey, Marmoset, Mouse, Rat, Elephant, Panda, Dog, Bat, Bovine, Horse, Pig, Opossum (100%); Rabbit (94%); Xenopus (82%).