Item Value
Test name Protein S Activity
Available Stat? No
Turn around times Run once per week. Turnaround 6-10 days
Performed by UC Davis
Normal range Age
Newborn - Day 4 12-60%
Day 5 - 1 Month 22-78%
1 Month - 3 Months 33-93%
3 Months - 6 Months 54-118%
> 6 Months 70-119%
Container type Blue top filled to full extent of vacuum
Amount to Collect 2.7 mL blood
Collection Instructions 1. Check the expiration date on the label of the blue top vacutainer before drawing the patient.

2. For blood collection in a sodium citrate blue top, the tube must be filled to above the Minimum Fill Indicator on the tube. It is crucial to wait and allow the tube to stop filling before removing it from the needle.

3. With use of a butterfly needle, draw about 1 cc using a separate blue top to remove air from tubing, discard the first tube and then draw a second blue top tube filled to the full extent of the vacuum.

4. Tubes should not be filled past the Maximum Fill dashed line by either using a syringe or removing the tube cap.

Avoid hemolysis

For patients with Hct's ≥ 55% please contact Hematology (415-353-1747) to obtain blue top tubes with adjusted citrate volumes in order to maintain the proper citrate to plasma ratio for coagulation studies.
Sample type Citrated plasma

If you have additional questions regarding this test, please call: 415-353-1667