Soon, you won't have to go to the doctor to find out whether your scratchy throat is strep. Using a kit now awaiting approval by the Food and Drug Administration, you can stick a swab down your throat, put the sample in a small container with some chemicals, and wait a few hours for a verdict. The $10 kit, developed by Personal Diagnostics Inc., of Whippany, N.J., will save you the trouble and cost of a visit to the doctor.

The strep-throat kit is one of several products that are bringing the doctor's house-call back -- without the doctor. Pregnancy tests are the best-known, but Personal Diagnostics alone has five mini-labs awaiting FDA approval. They test for urinary tract infections, diabetic blood-glucose imbalance, and fertility, as well as strep throat and pregnancy.

One kit uses a novel test to aid in conception. It analyzes a woman's saliva each morning, measuring hormones that vary with the menstrual cycle; a tiny computer chip predicts when ovulation will occur. Personal Diagnostics, which expects sales of $7 million to $10 million this year, says that about 75% of women in preclinical trials found the kit helpful.

C.B. Fleet Co., of Lynchburg, Va., introduced a home test for hidden blood in the stool, which can be an early symptom of colon-rectal cancer, as well as colitis, hemorrhoids, diverticulitis, or a gastric ulcer. The American Cancer Society recommends that people over the age of 50 have such a test annually. Fleet's kits have been available for just over a year and retail for less than $6.

The home-kit makers may encounter resistance among people who put faith only in their doctors. An army of hypochondriacs, though, is surely waiting to make these companies rich.