1. Blood sample processing for serum total cholesterol, HDL cholesterol and plasma glucose, HbA1c and DNA extraction

2. Based on EHES Manual, Part B. Fieldwork Procedures, 2nd edition (2016)
Available at:
These slides can be used freely, translated and adapted to national use (e.g. concerning the equipment). However, it is important to keep in mind that no changes should be made to the measurement techniques, which need to be standardized.

3. Equipment
Centrifuge
Empty tubes for re-centrifugation (only needed if gel serum tubes are used)
Storage tubes
Pipette
Storage boxes
Disposable gloves

4. Before centrifugation of blood tubes
After blood drawing store the tubes at room temperature in a vertical position at least 30 minutes for the blood in serum tubes to be clotted.
Do not prolong the waiting time over 60 minutes!
Adjust centrifuge speed g RCF

5. Centrifugation of blood tubes (1/2)
After the waiting period, centrifuge
The serum tube
The fluoride-citrate tube
The 1st EDTA tube
Do not centrifuge the last two EDTA tubes designated for HbA1c and DNA extraction!

6. Centrifugation of blood tubes (2/2)
Place the serum tube and the fluoride-citrate and the 1st EDTA plasma tube in the centrifuge
Check that all tubes are resting on the bottom of the centrifuge rack
Check that the centrifuge rotor and tubes are in balance.
Centrifuge the tubes 2000 g for 10 minutes at room temperature

7. Sample handling after centrifugation
After the centrifugation, check that the serum is separated properly
Pour the serum from the 2 serum collection tubes into the pooling tube, mix gently by swirling the contents
Note! If one of the serum tubes is haemolysed, do not mix them together

8. Labelling storage tubes
Place the storage tubes in a tube rack according to the pipetting scheme
No need to label all tubes if blood collection is incomplete
Place the bar code labels in an upright direction, so that the scale marks remain visible

9. Handling blood collection tubes with gel
The temperature during centrifugation should be at least °C
Inspect the gel tube after centrifugation for:
Gel surface horizontal
Serum and cell layers separated clearly
No red cells visible on top of the gel
No fibrin strands in the serum
Serum liquid, not clotted

10. Hemolysed samples
Do not pool a hemolysed serum sample with non-hemolysed samples
Several hemolysed samples can be pooled
Document hemolysed aliquots
Use the colour guide to document the degree of hemolysis

11. Pipette aliquots into storage tubes
2 x 1,5 ml serum from the pooling serum tube into the 3 ml plastic tube and 1,5 ml aliquots into the 1,5 ml storage cryotubes
2 x 1 ml from fluoride-citrate plasma tube into two 1,5 ml cryotubes
2 x 1,5 ml from the EDTA tube into two 1,5 ml cryotubes
Close the cryotubes with caps and freeze the tubes at once

12. Transferring storage tubes into freezers
Place the tubes without delay into the boxes in the freezer Label boxes before placing them into the freezer because labels will not stick on a wet/cold surface

13. Sample shipment To the national HES laboratory In dry ice
Packed in leak proof secondary packaging
To the EHES Reference Laboratory (if possible)
Packed according to the IATA regulations, according to Pecking Instruction 650 for diagnostic specimens
Place one tube upside down in every box

14. Recording The amount of the collected serum and plasma
Visible attributes (haemolysis, lipemia, icterius)
Deviations from the sample processing protocols, if any
Your initials/personnel code to identify who handled the samples

15. Acknowledgements Slides prepared by: Laura Råman
Photographs: Hanna Tolonen
Sample processing demonstrations by Saara Vallivaara
Experiences and feedback from the EHES network have been utilized in the preparation of these slides
Funding: Preparation of the slides is part of the activities of the EHES Coordinating Centre which has received funding from the EC/DG SANTÉ in through SANCO/2008/C2/02-SI EHES and Grand Agreement number , and in through Grand Agreement number /BRIDGE Health

16. Disclaimer
The views expressed here are those of the authors and they do not represent the Commission’s official position.