3-O-Methylguanosine (Standard) is an analytical standard of 3-O-Methylguanosine (HY-W091784). This product is intended for research and analytical applications. 3-O-Methylguanosine is a methylated nucleoside analog and RNA chain terminator. 3-O-Methylguanosine can inhibit the synthesis of early vaccinia virus-specific RNA[1].