BENTO

BIOLOGICAL MATERIAL

QUALITY SAMPLES

The primary mission of BQC19 is to provide the scientific community with biological samples and clinical and experimental data from COVID-19 patients and control participants. To guarantee sample quality and uniformity, the BQC19 has implemented standardized laboratory procedures for the collection of biological material, applied consistently across all its participating sites.

SAMPLING

The optimal collection of blood samples for BQC19 includes one PAXgene© tube, three ACD tubes and one red-capped or SST tube. Samples should remain at room temperature before processing, with an ideal delay of less than 6 hours between collection and processing, although a maximum delay of 12 hours is tolerated for most analyses. Delays in excess of 12 hours compromise the reliability of many analyses.

 

TYPES OF BIOLOGICAL SAMPLES

BQC19 offers a variety of biological samples derived from blood samples, including:

  • RNA extracted from PAXgene© tubes
  • DNA extracted from whole blood on ACD
  • Serum from red-capped or SST tubes
  • Plasma from ACD tubes
  • Peripheral blood mononuclear cells from ACD tubes

BQC19 also offers specific samples (heparinized plasma and plasma on EDTA) collected in limited quantities from residual clinical samples. Pediatric specimens are also available in limited quantities.

Samples are distributed between provincial and local collections in proportions defined in the management framework. The results of analyses carried out on these samples must be transmitted to the BQC19 , thus enriching the database shared with the scientific community.

RNA

Whole blood collection for BQC19 is performed in PAXgene© tubes, where 2.5 ml of blood is collected in a conservative medium to preserve RNA.

These tubes are first stored at room temperature for 24 hours, then transferred to -20ºC for one day before being stored at -80ºC for long-term preservation.

RNA is extracted at the McGill Genome Centre, following QIAGEN protocols, producing an eluate of approximately 80 µl with an average concentration of 116 ng/µl. RNA extracts will be supplied according to the needs of the researchers and the quantity of RNA available.

DNA

Blood samples for DNA extraction in BQC19 are collected in ACD tubes at the time of participant recruitment.

Whole blood is transferred to a single tube and two 0.5 ml aliquots are collected in cryopreservation tubes for DNA extraction. These samples are stored at -80ºC.

DNA extraction is performed at the McGill Genome Centre from 0.4 ml whole blood using the Perkin Elmer Chemagic method and the CMG-1091 kit. The final elution volume is 200 µl, with an average DNA concentration of 43.5 ng/µl and an average quantity of 8200 ng. DNA extracts will be supplied to researchers on an as-needed and as-available basis.

Genomic analyses were performed by BQC19. Full genome sequencing (WGS) and genotyping (GWAS) results are available via a data access request.

PLASMA

Plasma in BQC19 is mainly collected on aur tube ACD, with preference given to this method to facilitate the recovery of peripheral blood mononuclear cells (PBMCs). Spot samples of plasma on heparin and EDTA are also collected, but in limited quantities, from remaining clinical samples.

Plasma is separated by centrifugation at 850 g for 10 minutes at room temperature without a brake, then carefully aspirated to avoid aspiration of white blood cells.

It is then transferred in 0.25- or 0.5-ml aliquots into cryopreservation tubes, and stored at -80ºC for long-term storage. The total volume collected ranges from 4.5 ml to 15 ml.

Plasma samples are available to the scientific community via an access request, and aliquots are provided according to the researcher’s needs and the quantities available.

Proteomic, metabolomic, immunoserological and laboratory analyses have been carried out by BQC19. All results are available via a data access request.

PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS)

Peripheral blood mononuclear cells (PBMCs) are isolated after centrifugation during plasma collection, using either the Ficoll-Hypaque method or the alternative SepMate method.

Once isolated, PBMCs are frozen in a solution of FBS 20% DMSO, then stored in cryopreservation tubes at a final concentration of 10 million cells per ml. Tubes are first transferred to -80ºC for 24 hours, then stored long-term in liquid nitrogen.

PBMC collection capacity varies, but the median number of aliquots is two, one of which is dedicated to provincial collection.

Access to PBMC samples is by request, with aliquots of around 10 million cells per ml provided according to the researcher’s needs and the availability of quantities.

SERUM

Serum samples for BQC19 are collected from SST tubes or red-capped tubes, with collection volumes ranging from 4 to 10 ml, depending on tube type. The BQC19 has no serum samples for participants with severe disease from the first wave of the COVID-19 pandemic.

After centrifugation at 2000 g for 10 minutes at room temperature, the serum is separated and transferred in 0.25 ml or 0.5 ml aliquots to cryopreservation tubes. Samples are then stored at -80ºC for long-term storage. The number of aliquots and volume may vary according to the clinical situation of participants, particularly those with severe disease.

Access to these samples is by request, and aliquots are provided according to the researcher’s needs and the availability of quantities.