Today, laboratory testing is performed in many different settings, from the large, highly automated central laboratory that performs thousands of tests a day to your own home, where you might do a pregnancy test or monitor your blood glucose levels.

You may wonder where your tests are actually going to be done. As we take a more active role in our medical care, a clear understanding of what happens when our blood or urine samples are sent "off to the lab" will help us become more knowledgeable participants in our own health care.

All laboratories are not the same for the simple reason that not all tests are the same. Just as tests vary in complexity, and the technology needed to perform them, so too laboratories vary in their complexity, the numbers and types of tests they can perform, the professionals who staff them and the technology they have available.

The following descriptions explain some of the important differences between the various testing settings. We hope they provide a useful addition to your understanding of laboratory testing. For more information, see the "What happens to my blood sample?" page.