mysql string sanitisation

[Red Squirrel]

What would be the best/fastest way to sanitize strings?

Right now I wrote this function, but I don't know how efficient this really is, nor if I'm even covering all my bases:

		public static string Sanitize(string instr)
		{
			string ret=instr;
			
			ret=ret.Replace("\\","\\\\");
			ret=ret.Replace("\"","\\\"");
			ret=ret.Replace("`","\\`");
			ret=ret.Replace("\'","\\'");			
			
			return ret;
		}

Is there a better way to do this?