Test Code PTTMIX Activated Partial Thromboplastin (APTT) Mixing Study, Plasma
Performing Laboratory
Chilton Hospital Laboratory-Hematology
Methodology
Clot Detection
Specimen Requirements
Specimen must be tested within 4 hours of draw.
Specimen Type: Plasma
Container/Tube: Light-blue top (3.2% sodium citrate)
Specimen Volume: 2 full tubes
Collection Instructions:
1. Do not draw from an arm with heparin lock or heparinized catheter.
2. If specimen must be drawn from central line, flush with saline; and discard the first 5 mL of blood.
Additional Information:
1. If specimen cannot be delivered to the laboratory in the proper time period, spin down (within 1 hour of draw) at 6,000 rpm for 5 minutes.
2. Remove plasma and place in a plastic transport tube.
3. Label tube with patient’s name and time of collection.
4. Freeze plasma at -20° C and send to laboratory frozen.
Forms: Laboratory Misc. (CMH Graphics Arts #110-10 401) in Request Forms in Special Instructions.
Specimen Rejection:
1. Clotted blood
2. Insufficient specimen
Specimen Transport Temperature
Whole blood-Ambient
Plasma-Frozen
Reference Values
APTT
23.6-36.1 seconds
Critical value (automatic call-back): >100 seconds
Day(s) Test Set Up
Monday through Friday (7 a.m.-11a.m.)
Turnaround Time:
Routine-8 hours
Available STAT