Blood sample collection and processing SOP: EDTA to plasma

Baseline visit and Final visit

Blood sample collection

(3 extra EDTA [5Ml] added to protocol)

Samples sent to the investigation centre laboratory for outcome analysis

Results assessed by the research team according to each institution SOPs

Preparation of samples for blood storaging

Registration of time, date and participant’s ID when samples are received. Blood should be ideally processed within 30 minutes to 2 hours of being drawn.

Organization of the set of tubes in a test tube rack, one rack per participant. Researchers will use 11 microcentrifuge tubes per participant at each visit (1 microcentrifuge tube for whole blood and 10 microcentrifuge tubes for plasma).

Labeling of sample information on each tube (date, participant’s ID, study’s milestone baseline or follow up, type of sample - whole blood or plasma).

Set high-speed centrifuge to 4oC prior to use (10-15 minutes before procedure).

Gently invert the EDTA several times (8-10 time) after each tube is drawn.

Transfer of 1ML of whole blood from one EDTA into one microcentrifuge tube (using a 5 mL serological pipette tip and autopipettor)

Centrifugation of the remaining content of blood in the 3 EDTA (pre-cooled and balanced centrifuge). Spin conditions: 4°C, 5000 rpm for 15 min.

Tube removal from the centrifuge without disturbing the sample. Transfer of 0,5Ml of plasma from the EDTA into each of the remaining 10 microcentrifuge tubes (using a 5 mL serological pipette tip and autopipettor)

Finalization process: close the cap, shake and dispose of the EDTA in a biohazard waste container. Sample storage in the freezer box, completion of form (Blood Collection and Processing map), marking the corresponding spot where it has been stored.

Storage of both the plasma and whole blood at -80oC, while the red blood cells will be discarded