This rapid Strep A Test is great tool for families with kids who get frequent sore throats. It helps you determine whether a throat infection is caused by strep (which requires treatment) or a virus (which does not). You swab the back of the child’s throat with the included applicator, add a reagent, and watch for the color change. A kit of 25 tests costs about $50, which works out to about $2 per test. That’s a whole lot is much cheaper than an unneeded doctor’s visit. But since you may only use a couple tests a year, consider a cooperative buy with other families.