Cytarabine (hydrochloride) (Standard) is the analytical standard of Cytarabine (hydrochloride). This product is intended for research and analytical applications. Cytarabine hydrochloride, a nucleoside analog, causes S phase cell cycle arrest and inhibits DNA polymerase. Cytarabine inhibits DNA synthesis with an IC50 of 16 nM. Cytarabine hydrochloride has antiviral effects against HSV.