Laboratory Test Information Guide

Details for Protein S Antigen (Free)

Test Name: Protein S Antigen (Free)
Alternate Name(s): PSF
Laboratory: Hemostasis and Thrombosis Laboratory (Victoria Hospital)
Specimen Type: 2.7 mL Blue (3.2% Sodium Citrate) top Vacutainer tube

Pediatric:
0-2 years: 1.8 mL Blue Sodium Citrate Coagulation tube:
Contact HAT lab ext. 52526 for number of tubes required prior to sampling
Collection Information: LHSC patient samples require authorization by a Hematologist.
Requisition: GENERAL LABORATORY REQUSITION
Test Schedule: Weekly
Turnaround time from when specimen
is received in testing laboratory:
 
Routine
2 weeks
Stat
N/A
 
Reference Range: Adult: 0.60-1.40 U/mL
Effective Date:  
Revised Date: 2018-10-23
Critical Value:  
Interpretive Comments: Testing not recommended during Warfarin therapy and in pregnancy.
Special Processing: Blue (Sodium Citrate) top tubes should be centrifuged within 4 hours of collection.

The blood specimen must be double centrifuged to prepare platelet free plasma.

Centrifuge the primary tube or tubes for 10 minutes at 3000 rpm, aliquot and re-spin for an additional 10 minutes at 3000 rpm at room temperature (18 to 20 degrees Celsius). Ensure the temperature does not exceed 20 degrees Celsius.

The double-centrifuged plasma is aliquoted into plastic tubes labelled with the appropriate Cerner generated aliquot label and frozen immediately at -20 degrees Celsius or below.

SRA Processing:

UH/SJH All shifts:
Log in samples and bring INR/PTT sample to the Coag Bench. Process the rest of the samples as per the procedure above. Place samples/aliquot labels with transfer list in the SPEC COAG Bin in the -20C freezer. All samples to be sent to VH SRA the following morning. Upon arrival VH SRA will place the samples in the -20 bin. The HAT staff will pick up the samples.

VH 0700-1500 shift:

Log in samples and bring INR/PTT sample to the Coag. Bench. Place the rest of the samples/aliquot labels in the pneumatic tube and send to the 10th floor HAT Lab at VH. (No transfer list is required). Call HAT Lab at ext. 52526 to let them know a sample is coming.

VH after 1500:

Log in samples and bring INR/PTT sample to the Coag Bench. Process the rest of the samples as per the procedure above. Place samples/aliquot labels in the SPEC COAG Bin in the -20C freezer. All samples will be picked up the following morning by the HAT staff.

VH Referred-In samples:
When a sample is received from an outside healthcare institution, please order SPCOAGRI, put a small accession label on the requisition, then place the frozen samples and labels in the SPEC COAG Bin in the -20 freezer. Please send the requisition with the accession number on it, to the 10th floor. These samples will be held until the next morning and picked up by the HAT Lab staff. If the HAT Lab staff require a sample earlier then the next morning, they will come down and get it. Call the HAT Lab at ext. 52526 to let them know the requisition is arriving.
Comments: Level is decreased in Protein S deficiency, a prothrombotic condition.
Method of Analysis: Automated light trasmitance assay
Critical Information Required: Anticoagulant therapy
Storage & Shipment: Blue (Sodium Citrate) top specimens are kept at 18-24 degrees Celsius.

Blue (Sodium Citrate) top specimens should be centrifuged and tested within 4 hours from the time of specimen collection or plasma should be removed from the cells and frozen.

Specimens may be kept for up to two weeks at -20 degrees Celsius or up to six months at -70 degrees Celsius.

Plasma aliquots are stored at -20 degrees Celsius or below and transported to arrive frozen.

Once received by the Sample Receiving Department at Victoria Hospital, samples are to be stored at -70 degrees Celsius within 15 minutes.
System Codes: 
Cerner
PSAG
 
Referred To:  

Questions? Comments? Contact Laura Gopaul