Development Class C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
public static class UtilityExtension
{
    public static readonly Regex guidRegEx = new Regex(@"^(\{{0,1}([0-9a-fA-F]){8}-([0-9a-fA-F]){4}-([0-9a-fA-F]){4}-([0-9a-fA-F]){4}-([0-9a-fA-F]){12}\}{0,1})$");
    public static bool IsGuid(this string expression)
    {
        if (!String.IsNullOrEmpty(expression))
        {
            return guidRegEx.IsMatch(expression);
        }
        return false;
    }
}