Platelet Function Assay (PFA)

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Testing Laboratory

Waitematā | Northshore Hospital

Department

Haematology

Delphic Registration Code (Alpha Code)

PFA, FBC, NCOA

Test Code (Numeric Code)

1820

Laboratory Handling

Phlebotomy

Tube must be filled up to the "Fill Line"

Transport

PFA samples must not be sent via Lamson system (Hand-deliver only)

Registration

Waitakere - please send to North Shore by taxi (1-0800-228 294) When sending PFA from Waitakere to NSH send a photocopy of the request form. Send using an insulated container to protect specimen from heat. Notify NSH Coagulation department on ext. 42327. If the tubes are not numbered, do not spin any of the citrate tubes. Give them all to Coagulation to sort.

Separating

Do not spin

Sample Stability

Sample must be processed within 4 hours of collection and kept at room temperature at all times

Associated Tests

Synonyms

PFA

Turnaround Time

2 hours

Specimen Type

  • Whole Blood

Specimen Requirements

Tube/Container Type:

Preferred
  • Citrate (Light Blue Cap)
  • EDTA (Lavender Cap)
Preferred Sample Volume (ml)

2.7

No of Samples Required

3

Paediatric Specimen Requirements

Tube/Container Type:

Preferred
  • Citrate (Microtainer)
  • EDTA (Microtainer)
Minimum Sample Volume (ml)

1

Additional Specimen Information

Please collect 2 x Citrate (Blue) AND 1x EDTA (Purple)

Collect with minimum trauma using 21G needle.
Label citrate tubes in order of draw. Write 1,2, etc in the space next to DOB.
Please note, there must be 2 Citrate tubes collected.
1. 1st citrate tube = for coag screen
2. 2nd citrate tube = PFA

Sample must be processed within 4 hours of collection and kept at room temperature at all times.
Test performed on whole blood. If the sample has been spun for clotting screen then it cannot be used for PFA.

Tubes must be filled up to the ""Fill Line"" and labelled ""1"" and ""2"" in order of draw.

Place PFA bloods in a separate bag with **""Do Not Spin""** notice and Urgent sticker.
Notify the Haematology department (ext. 42327) to prepare the machine. **""Hand deliver immediately to the laboratory.""** Do not send via the Lamson system as this may cause platelet activation.

Last updated: 27/10/2026