Assay Menu
Shear Induced Platelet Activation and Aggregation
Shear Induced Platelet Adhesion and
Aggregation on Subendothelial Matrix
Platelet Activation
Anti-Platelet Blockade
Platelet Receptor Expression
Clot Retraction
Platelet Aggregation
Thrombosis Risk Assays
Routine Coagulation Screening
Heparin Monitoring
Coagulation Factor Analysis
Fibrinolysis Evaluation
Genetic Factors
Basic Blood Parameters
Thrombosis Core Laboratory Equipment
NOTE:
- Normal ranges have been established from 250 healthy male and female adult donors form the greater Houston area.
- C.V.s have been established for all assays and most within-run variations are <2 percent and within-day variations are <10 percent.
- The TCL is able to offer customized assays that meet the needs of individual investigation incubation time and antibody as needed by the investigator.
- Several platelet assays have been optimized for thrombotic risk testing.
- For local users, we have a dedicated room for phlebotomy with a comfortable reclining J7AB Medical Chair. Alternatively, our trained phlebotomist can come to your patient.
- Contact the TCL at 713-798-5950 for shipping instructions.
Shear Induced Platelet Activation and Aggregation
| Measures: | Platelet aggregate formation |
| P-selection expression | |
| Viscosity | |
| Microparticle formation | |
| Threshold shear force required for aggregation | |
| Time to disaggregation | |
| Instrument: | Haake cone and plate viscometer |
| Assay: | Variable shear rates are applied to the sample; typically 0, 500, 1000, 2000, 5000, and 1000 sec-1 |
| Anticoagulant: | Citrate, PPACK, acid citrate dextrose (ACD) |
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Shear Induced Platelet Adhesion and Aggregation on Subendothelial Matrix
| Measures: | Time to closure |
| Volume of blood passing through hole prior to closure | |
| Instrument: | PFA-100 |
| Assay: | fixed shear 1500 sec-1 applied to blood over a collagen substrate and through a pinpoint hole; epinephrine and ADP embedded on substrate |
| Sample: | Whole blood |
| Anticoagulant: |
Citrate, PPACK, acid citrate dextrose (ACD) Note: Specific experiments may also be conducted in parallel plate flow chamber under variable shear rate, and on different matrix proteins. Other agonist induced. |
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Platelet Activation
| Measures: | P-selectin expression |
| GPIIb-IIIa activation (PAC1 binding) | |
| Microvesiculation | |
| Platelet-Leukocyte Interactions | |
| Other activation-dependent antibodies | |
| Dense granule (ATP) release | |
| Ionized Calcium Flux | |
| Instruments: | Coulter® EPICS® XL-MCL™ Flow Cytometer |
| Chronolog aggregometer | |
| Assay: | A range of agonist concentrations is used |
| Sample: | Whole blood or PRP |
| Anticoagulant: | Citrate, PPACK (default), acid citrate dextrose (ACD) |
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Anti-Platelet Blockade
Measures the efficiency of anti-platelet agents.
| Drug: | Method: |
| Aspirin | Urinary ThromboxaneA2 |
| Arachidonic Acid | Lumi-aggregometry |
| Integrilin (Eptifibatide, GPIIb-IIIa inhibitor) | Lumi-aggregometry |
| Abciximab (Reopro, GPIIb-IIIa inhibitor) | Lumi-aggregometry |
| Aggrastat (Tirofiban, GPIIb-IIIa inhibitor) | Lumi-aggregometry |
| Clopidogrel (ADP receptor inhibitor) | Lumi-aggregometry |
| Ticlopidine (ADP receptor inhibitor) | Lumi-aggregometry |
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Platelet Receptor Expression
Measures number of platelet surface proteins.
| Adhesion Receptors : | Ligand: |
| GPIIb-IIIa (integrin alphaIIbbeta3) | Fibrinogen, von Willebrand factor |
| GPIbalpha | Von Willebrand factor, thrombin |
| GPIa-IIa |
Collagen |
| GPVI | Collagen |
| Others: | |
| FcgamaRIIa | IgG |
| alpha2-adrenergic receptor | Epinephrin |
| Any other platelet surface molecule for which there is a specific antibody | |
| Instrument: | Coulter® EPICS® XL-MCL™ Flow Cytometer |
| Assay: | A range of agonist concentrations can be used |
| Sample: | Whole blood or PRP |
| Anticoagulant: | Citrate, PPACK, acid citrate dextrose (ACD) |
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Clot Retraction
Measures: extent of clot retraction at two hours.
Sample: Whole blood or platelet rich plasma
Anticoagulant: citrate, PPACK (default), acid citrate dextrose (ACD)
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Platelet Aggregation
Measures extent of platelet aggregation.
| Agonist: | Typical Concentrations : |
| None (spontaneous aggregation) | |
| Epinephrine | 0.1, 0.2, 0.4, 1.5, 3.0, 10 µM |
| Collagen | 2.5, 5.0, 10, 20, 50 µg/ml |
| ADP | 0.05, 0.5, 1.0, 4.0, 20.0 µM |
| Ristocetin | 0.1, 0.5, 0.75, 1.0, 1.5 mg/ml |
| Arachidonic acid | 0.5 mg/ml |
| Instruments: | Platelet aggregation profiler® PAP-4D |
| Chronolog whole blood/Lumi aggregometer | |
| Sample: | Platelet rich plasma or whole blood |
| Anticoagulant: | Citrate, PPACK (default), acid citrate dextrose (ACD) |
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Thrombosis Risk Assays
- Activated Protein C resistance
- Lupus Anticoagulant (dRWT and Confirm)
- Protein C activity
- Antithrombin III activity
- Prothrombin fragment 1+2 (PF1+2)
- Thrombin-antithrombin complex (TAT)
- PT
- INR
- aPTT
- Mixing Studies
- Thrombin Time
- Fibrinogen
- Anti-Xa
- aPTT
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Coagulation Factor Analysis
- Fibrinogen Activity
- vWf activity (Ristocetin Cofactor)
- Factor V Activity
- Factor VII Activity
- Factor VIII Activity
- Factor IX Activity
- Factor X Activity
- Factor XI Activity
- Factor XII Activity
- Fibrinogen Activity
- Factor VII Antigen
- Factor X Antigen
- Factor X Chromogenic
- Fletcher Factor Assay (Prekallikrein)
- High Molecular Wt. Kinnogen Assay
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Fibrinolysis Evaluation
- D-Dimer Semiquantitative
- D-Dimer Quantitative
- Fibrin Monomer
- Fibrinogen Degradation Products
- Plasminogen Antigen
- Tissue Plasminogen Activator Activity
- Tissue Plasminogen? Activator Antigen
- Euglobulin Lysis Time
- Plasminogen Activity
- Plasminogen Antigen
- Plasminogen Activator Inhibitor-1 (PAI-1) Activity/Antigen
- alpha2 antiplasmin
| Platelet Polymorphisms : | Protein/Gene: |
| PlA (HPA-1) | GPIIIa |
| Ko (HPA-2) | GPIbalpha |
| Bak (HPA-3) | GPIIb |
| Pen (HPA-4) | GPIIIa |
| Br (HPA-5) | GPIa |
| His131Arg | FcgRIIa |
| 807 T/C | GPIa |
| VNTR | GPIbalpha |
| Kozak (-5 T/C) | GPIbalpha |
| CA repeat | Estrogen receptor ß |
| Long/short | alpha2-adrenergic receptor |
Other mutations/polymorphisms can be detected on a custom basis.
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Basic Blood Parameters
- CBC
- Mean Platelet Volume
- Mean Platelet Surface Area
- Viscosity
- Hematocrit
Thrombosis Core Laboratory Equipment
1. Coulter® EPICS® XL-MCL™ Flow Cytometer
2. ABI Prism 7700 Sequence Detector (real time PCR instrument)
3. HAAKE RheoStress I (RSI) Rheometer
4. Parellel-plate flow chamber system
5. Coulter Z2 (particle count and size analyzer)
6. BioData 4 channel Platelet Aggregation Profiler® PAP-4D (two)
7. Chronolog Whole blood/Lumi Aggregometer
8. Dade Behring BCS Coagulation Analyzer
9. Dade Behring PFA-100
10. BIO-RAD SmartSpec 3000 Spectrophotometer
11. Foto/Analyst Express Base System (Camera-Foto Imaging)
12. Transilluminator 8x16 w/ cover and photo hood
13. Storage capacity in liquid nitrogen, -80ºC and -20ºC