Clotting Screen

Pathology category

Haematology

Code

CS

Referral code

Request form

Test information

Must be analysed within 6 hours of collection

Guidelines

Pre-analytical

Lipaemic, jaundiced or haemolysed samples may present problems with testingSample transport should be at 4-25C and reach the laboratory ASAPPlease note: the samples must arrive the same day as collection otherwise they will be rejected by the laboratory

Reference range

Time is reagent dependentNormal ratio (INR) = 0.8-1.2Normal ratio (APTT) = 0.8-1.2

Tube type

Tube type info

2.7ml blue top citrate1.8ml blue top citrate with white cover (paediatrics)

Special requirements

NA

Minimum volume

1 tube minimum 90% full – essential to ensure correct 1:9 ratio of anticoagulant : blood

Assay frequency

Routine

TAT Inpatient (urgent)

1 hour

TAT Inpatient

4 hours

TAT GP/Outpatient

4 hours

Referral lab

NA