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Test Code RIPA Ristocetin-Induced Platelet Aggregation

Important Note

Prior appointment is required. Please call Haematology at 67725320 for appointment.

Patient should be fasting for this test.

Specimen Requirements

Submit the following specimen

Specimen Type: Whole Blood
Container/Tube: 1 Lavender Top (EDTA)
Volume: 3 mL whole blood                                                                                                        Minimum Volume: 1.5 mL Whole Blood
Collection Instructions: Please call Haematology to arrange for the collection of blood samples.

 

and

 

Specimen Type: Whole Blood
Container/Tube: 2 Light Blue Top (3.2% Sodium Citrate)
Volume: 2 × 2.7 mL whole blood (Tubes must be full)
Collection Instructions: Please call Haematology to arrange for the collection of blood samples.

Specimen Stability

Fresh specimen required

Specimen Type Whole Blood
Ambient 1 hour (preferred)
Refrigerate Reject
Frozen Reject

Specimen Condition

Gross Haemolysis Reject
Gross Icterus Reject
Gross Lipaemia Reject
Others: Clotted or insufficient specimen Reject

Methodology

Platelet Aggregometry

Days and Times Performed

Monday 9am, TAT 5 days

Reference Interval

Normal platelet agglutination response to high dose ristocetin
Absent platelet agglutination response to low dose ristocetin

Testing Laboratory

National University Hospital

Haematology, 67725320

Useful For

Aids in the diagnosis of variant von Willebrand’s Disease (especially Type 2 VWD).

Service Code

12437

Update

Last updated 14/01/2026

Panel Information

Panel includes the following agonists:

  • High Dose Ristocetin
  • Low Dose Ristocetin

Alias

RIPA

LOINC Code Information

LAB3052997

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