Laboratory
Laboratory tests must be ordered by a Northwestern Medicine Student Health Service practitioner. The Student Health Service Laboratory is staffed by medical technologists and phlebotomists. They and performs basic urinalysis, hematology, microbiology, and chemistry tests on site. The Laboratory is unable to accommodate walk-in lab tests after 4:30 pm on weekdays. TB blood testing must be performed before 4 p.m on. weekdays.
Other laboratory tests are sent to an outside reference laboratory. Many tests done on site are provided at no charge to eligible students. There is a charge for all other laboratory tests. Test results will be provided by the ordering clinician.
Frequently Asked Questions for Laboratory
The following information addresses frequently asked questions about the utilization of the Laboratory at the Student Health Service. Any other questions may be answered by If you have any questions, please calling the Laboratory directly at 847.491.2143.
How do I use the services available from the Laboratory?
You must have an order from a Student Health Service practitioner on the medical staff of the Health Service.
Do I have to pay for these tests?
Many lab tests done on site are provided at no charge. The exceptions are the pregnancy test, chlamydia, HIV, and rapid strep. Any test sent to our reference lab incurs a charge. This price has been negotiated and is substantially lower in comparison to the local community and the Chicago area.
I saw a physician outside of the Student Health Service and some tests were ordered. Can you do them here?
Yes, but you must first have a nurse visit to have the orders documented in your chart and rewritten. We do not accept orders from non-health service practitioners directly. You may call 847.491.2204 to schedule an appointment.
Do I need to make an appointment for lab tests?
No, the Laboratory is open from 8:30 a.m. to 5 p.m., Monday through Friday to walk-ins. However, if your practitioner has requested you to fast, you must go without food for at least 10 hours before having your blood drawn.
How can I get my lab test results?
Most results are available within 24 hours, often the same day. Some send-out lab tests may take longer. You may call your practitioner to discuss results and further treatment. Additionally, you may retrieve the results via the Personal Health Portal. Please do not call the Laboratory for your test results.
What is that stuff in the bottom of the tube?
In tubes used to collect blood for tests where serum is needed, a silicon gel is on the bottom of the tube. When the blood clots and is spun, the gel rises to separate the serum from the cells.
How much blood are you taking?
The smaller tubes collect about 5 milliliters, and the large tubes about twice that. Your body makes 30 milliliters of new blood each day.
Why do you have to take more than one tube of blood?
Some tubes contain an anticoagulant so the blood does not clot. Other tests use serum, so the blood is allowed to clot and then separated. Some tests require special preservatives in the tube.
Is this going to hurt?
Usually a stick to obtain blood hurts only while the needle is breaking the skin, not much and only for a second. It helps to look away.
What is a CBC?
A CBC is a complete blood count. It counts the number of of white blood cells (may indicate bacterial or viral infection) and hemoglobin (may indicate anemia). We also look at the types of white cells that you have. Sometimes we can detect mononucleosis (mono) this way.
What is the total amount of blood in my body?
The average amount is about 6 liters of which 45% is cellular and 55% is plasma, a fluid. About 90% of the plasma is water.
What is a Chemscreen?
This test, which we send to our reference lab, measures 25 different analytes found in our bloodstream. They include elements such as iron, sodium, and potassium; enzymes; and molecules such as glucose, cholesterol and protein.