How a Blood Sample Undergoes Laboratory Tests

If you've ever had blood drawn for a laboratory test, you probably haven't thought much about what happens to your blood after it leaves your vein. The technician takes the sample and about two weeks later, you get the results. But, how does the process work? Below, we follow a sample of blood from your arm to the laboratory for testing and back. Step 1 – A blood sample is taken from your arm and collected into a small tube. Step 2 – After collection, the tube is labeled. The label will include your name and what tests are to be run on the blood. Step 3 – Your sample arrives at the laboratory and your information is put into their computer. The label tells the laboratory what tests to run, but the tube is also accompanied by paperwork with your doctor's information so the results can find their way back. Step 4 – If the tests your doctor ordered require a component of the blood, like plasma or serum, the sample will be spun in a centrifuge to separate the components for testing. Step 5 – A machine called a blood analyzer will run the specified tests on your sample. Step 6 – The results are in. Some blood analyzers will process the results electronically so they can be emailed to your doctor, complete with graphics. In other cases, the results are simply printed and either mailed or faxed to the doctor.