Escaping <

Hey,
Does < need to be escaped? I have this regex:
Regex Rgx1 = new Regex(@"(\(*)(?:\s*)(?:(" + String.Join("|", SearchKeys) + @")?(?:\s*([><=:]+)\s*))?([A-Za-z0-9.*\-\\\/\s]+?)(?:\s*)(\)*)(?:\s*)(\bor|and\b|\z)(?:\s*)", RegexOptions.IgnoreCase);
But it is refusing to accept the < bracket when used alone. > bracket, = and colon are all fine, as is <> and <=.
These work:
string = hello<>world string = hello<=world string = hello>world
This doesn;t:
string = hello<world
Thanks