Houston Methodist. Leading Medicine.
Houston Methodist. Leading Medicine


Clinical Coagulation Specialty Testing

More information including sample requirements can be found in our Searchable Test Catalog.

Test Request Form

Please download and fill out an HMDL Coagulation Test Requisition (PDF format / Excel format). Place the sample and test request form in a sealed specimen bag.

Routine Coagulation Testing

Prothrombin Time (PT)
Partial Thromboplastin Time (PTT)
Thrombin Time (TT)
D-dimer, quantitative
1:1 mix (PT and PTT), with interpretation

Factor Assays

Factor II Activity
Factor V Activity
Factor VII Activity
Factor VIII Activity
Factor IX Activity
Factor X Activity
Factor XI Activity

Thrombophilia Assays

Antithrombin Activity
Protein C Activity
Protein S Activity
Protein S Free Antigen
Protein S Total Antigen
Factor V Leiden Mutation
Factor II (Prothrombin) Mutation
Lupus Inhibitor

Anticoagulant Monitoring

Direct Thrombin Inhibitor Activity (Dabigatran, Bivalirudin, Argatroban)
Unfractionated Heparin Activity (anti-Xa)
Low Molecular Weight Heparin Activity (anti-Xa)
Fondaparinux Activity (anti-Xa)
Rivaroxaban (Xarelto) Activity (anti-Xa)

Platelet Function Studies (patients must have blood drawn at Houston Methodist Hospital)

Platelet Aggregation
If possible please download and have the patient answer the Platelet Aggregation Assay – Patient Questionnaire and send with the patient or sample when ordering the test
Verify Now P2Y12
Verify Now Aspirin
Platelet Function Analyzer

von Willebrand Factor Assays

von Willebrand Factor Antigen
von Willebrand Factor Immunofunctional Activity
von Willebrand Factor Collagen Binding
von Willebrand Factor Multimers
von Willebrand Factor Ristocetin Induced Platelet Aggregation (VWD2B)
Factor VIII Activity

Research Assays (not for clinical use)

Thrombin generation
Microparticle analysis