See below. Two tests: one is a blood test which tests the level of uric acid in your blood. The second on is a test of the joint fluid in the affected joints or joint that looks for urate crystrals under a microscope. These crystals look like needles which can feel like needles as well.
Labs. Presumptive diagnosis of gout can be made by exam (swollen warm joint), labs (elevated serum uric acid levels) and history, definitive diagnosis requires analysis of an aspiration from the joint demonstrating appropriate "crystals".