A double-blind placebo-controlled food challenge, in which increasing quantities of allergen capsules and placebo capsules are administered under a doctor's supervision to test for a reaction, is considered the "gold standard." It's considered more accurate than either a blood test or a skin test.
Most often nuts. You can learn about testing for the allergy at http://www.peanutallergy.com/test-diagnosis.html
The quickest way would be for your vet to perform a allergy blood test which is very accurate.
Skin allergy testing is usually done by placing a series of adhesive patches on the skin containing potential allergens, or allergy-causing substances.
allergy test
Battery load test
Most are pretty accurate, but get one from the doctor and it will be truly accurate.
DNA paternity test is the most accurate testing . It has accuracy approximately 99.9 %
A test to see if you are allergic to dogs
The most accurate one is plan b.
Which blood test tube you need for shellfish allergy.
Ultrasonic bone density testing
Most pregnancy tests are accurate day one of your missed period, if your test is negative retake it in 3 to 7 days.