Test Code LAB4084 PARTIAL THROMBOPLASTIN MIX
Specimen Type
3mL Blue top (3.2% Sodium Citrate), or
5mL Blue top (3.2% Sodium Citrate)
Collection Instructions
Blue top Sodium Citrate tube filled to capacity. Must be performed within 4 hours of specimen collection or made into platelet poor plasma and frozen.
Specimen Volume
2 mL
Minimum Volume
1 mL citrated plasma
Turnaround Time
STAT: 1 hour
Routine: 4 hours
Test Schedule
Daily
Specimen Processing
Assays on nonheparinized patients must be performed within 4 hours of collection. Assays on specimens suspected to contain unfractionated heparin therapy should be centrifuged and the plasma removed from the cells within 1 hour of collection and tested within 4 hours of collection. If time interval between drawing and testing exceeds 4 hours, centrifuge specimen, separate plasma, recentrifuge, separate into plastic tube, and freeze at -20C or less.
Method
Electromechanical
Reference Ranges
APTT 1:2 - 0 MIN = 23.5 - 34.6 seconds
APTT 1:2 - 60 MIN = 23.5 - 34.6 seconds
Synonyms
Partial Thromboplastin Time Mixing Study
CPT Codes
85730
Rejection Criteria
Severely hemolyzed, clotted samples or inappropriately filled liquid blue top tubes, specimens more than 4 hours old that have not been separated and frozen at -20C or less.