Additional Referral/Aliquot Information
2 mL whole blood, to be sent to Specialist lab urgently, via hoist (phone 80332). After hours prepare in Separating area as per protocol below.
Send frozen prepared haemolysed cells
The red blood cells must be washed, haemolysed and frozen before they are 4 hours old (post venipuncture). Samples for analysis of thiamine are prepared by washing the red cells with isotonic 0.9% saline, preparing a red cell lysate and freezing.
METHOD
1.Centrifuge the sample at 3000 rpm for 5 minutes.
2.After centrifugation use a pasteur pipette to remove and discard the plasma and buffy coat layer.
3.The red cells are washed by adding an equivalent volume of isotonic saline (9 g/L NaCl) and mixing thoroughly.
4.Centrifuge the sample at 3000 rpm for 5 min.
5.Label a plastic tube suitable for transport, with the patient surname and laboratory number.
6.After centrifugation use a pasteur pipette to remove the top saline layer and 1 mm of red cells. Discard, leaving behind the washed red cells.
7.To the labelled tube add 1 mL of washed packed red blood cells (RBC) from the middle of the washed cells.
8.Using the same pipette tip, draw up 1 mL of distilled water and add this to the cells in the labelled tube.
9.Stopper, mix thoroughly by rolling the haemolysate around the inside of the tube.
10.Place the tube inside a plastic bag and freeze.
When frozen, send to laboratory.
