License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
For hazard information and safety warnings, please refer to the SDS (Safety Data Sheet).
Biosafety Notes
All materials required for sample processing are to be prepared in the biosafety cabinet before handling of blood samples.
All blood sample manipulation takes place in a biosafety cabinet unless specifically stated.
All centrifugation steps must take place in capped containers. Upon completion of a centrifugation step, return the capped container to the biosafety cabinet, remove all tubes, and spray and wipe them with >70% ethanol before continuing to the next step.
Preparing Buffer
Preparing Buffer
Create the following DPBS Solution-EDTA in a bottle of DPBS by using the table below:
Component
Volume (mL)
Starting Conc.
Final Conc.
DPBS
474
-
FBS
25
100%
5%
EDTA
1
0.5 M
1 mM
Table 1.
Preparation of Blood
Preparation of Blood
Place sample box into biosafety cabinet.
Remove samples from the box and from the containment bags, discard bags, spray sample containers with >70% ethanol and wipe down.
Record the total volume of whole blood to be processed in mL.
Spin the whole blood 400 x g, 20°C, 00:10:00 in the anti-coagulant tubes and remove the plasma layer to cryovials. Be sure to not remove any red blood cells with the plasma. Add the same volume to all cryovials.
Record number of vials: __________ and the volume per vial __________ mL.
Note
NOTE: Ensure that cryovials are decomtaminated prior to removal from the biosafety cabinet.
Add the same volume of DPBS Solution-EDTA as removed plasma back to the blood tube. Pipette to mix.
RosetteSep and Ficoll-Paque
RosetteSep and Ficoll-Paque
Add 50 µL RosetteSep Cocktail/1mL of blood directly to the blood tube. Pipette to mix.
Inclubate samples at Room temperature for 00:20:00.
Transfer sample to a 50 mL tube and dilute up to25 mL with DPBS Solution-EDTA solution.
Aliquot 15 mL Ficoll-Paque Media PLUS to a 50 mL tube.
Using the slow setting on the pipette gun, gently layer the blood/DPBS Solution-EDTA mixture on top of the 15 mL Ficoll-Paque Media PLUS. Take extra care not to disturb the blood-ficoll interface while layering. Disturbing the interface excessively prevents the mononuclear cells from becoming a clean layer.
Spin for 1200 x g, 20°C, 00:20:00 with no brake, 4 acceleration.
Note
NOTE: Centrifuge should be pre-warmed to 20 °C.
Remove the mononuclear cell layer from each tube and transfer to a new 50 mL tube. Take extra care to avoid pulling cells from the ficoll layer (underneath the mononuclear cell layer) as this typically contains a lot of granulocytes. Pulling from the plasma layer is not an issue.
Top PBMC with cold DPBS Solution-EDTA to40 mL (ensure at least 2-3 volumes are added) and centrifuge the cell suspension(s) for 400 x g, 4°C, 00:10:00.
(Platelet Spin) Discard the supernatant, top tubeto 40 mL with cold DPBS Solution-EDTA, and centrifuge the cell suspension for 120 x g, 4°C, 00:10:00.
Remove the supernatant (caution: pellet may be loose), and resuspend the cell pellet in 4 mL Dulbecco’s Phosphate Buffered Saline (DPBS).
Cell Counting of COVID Samples
Cell Counting of COVID Samples
Add 0.05 mL sample, 0.05 mL DPBS, and 0.005 mL Solution 13 to a 1.5 mL centrifuge tube, incubate for 00:02:00 at Room temperature.
Add 0.1 mL BD Cytofix Fixation Buffer to the samples and incubate 00:30:00, 4 °C, and protect from light.
Aliquot 0.01 mL sample to the well of a NC-Slide A8 and count on the NC-3000.
Record number and viability below, calculate total cells:
Aliquot up to 2 x 107 cells to a 5 mL Falcon Round-Bottom tube and place On ice for subsequent sample clean-up (next section).
Freeze down up to 1 x 108 cells in approximately 1 x 107 aliquots (1 mL each) using Cryostor CS10 Medium, a Mr. Frosty, and a -80 °C freezer.
Record the number of vials frozen: __________ and the cells per cryovial frozen: _________.
Sample Clean Up for scRNAseq – CD66b and CD235ab removal
Sample Clean Up for scRNAseq – CD66b and CD235ab removal
Centrifuge the single cell suspension for 400 x g, 4°C, 00:05:00.
Discard the supernatant and resuspend the cell pellet in 50 µL DPBS Solution-EDTA.
Add 10 µL Human TruStain FcX to the single cell suspension and incubate for 00:10:00, 4 °C.
Add 10 µL biotinylated anti-CD66b and biotinylated anti-CD235ab to the sample and incubate for 00:30:00, 4 °C.
While the single cell suspension is incubating add 0.2 mL BioMag Plus Streptavidin Beads to a 5 mL Falcon Round-Bottom tube.
Add 2 mL DPBS Solution-EDTA to the BioMag Plus Streptavidin Beads and place on a magnet for 00:05:00.
Remove all the supernatant from the BioMag Plus Streptavidin Beads, remove from the magnet and resuspend the beads in 0.1 mL DPBS Solution-EDTA.
Once step 25 (go to step #25) is complete, add 3 mL DPBS Solution-EDTA to the single cell suspension and centrifuge for 400 x g, 4°C, 00:05:00.
Resuspend the single cell suspension in the BioMag Plus Streptavidin Beads from step 28 (go to step #28), and incubate at Room temperature for 00:05:00.
Add 3 mL DPBS to the tube and place on a magnet for 00:05:00.
Remove supernatant from tube and transfer to a separate 5 mL Falcon Round Bottom tube.
Sample Clean Up for scRNAseq – Dead Cell Removal
Sample Clean Up for scRNAseq – Dead Cell Removal
Centrifuge the single cell suspension for 400 x g, 4°C, 00:05:00, and discard supernatant.
Resuspend cell pellet in 0.1 mL Dead Cell Removal Microbeads, mix well, incubate, Room temperature, 00:15:00.
While the cell suspension is incubating, place an MS Column onto the MACS Multistand and rinse with 0.5 mL 1x Binding Buffer Solution.
Post incubation, apply cell suspension to the MS Column and capture the flow through in a 5 mL Falcon Round Bottom tube.
Rinse with 1.5 mL 1x Binding Buffer and capture in the same tube.
Centrifuge the single cell suspension for 400 x g, 4°C, 00:05:00, and discard supernatant.
Resuspend cell pellet in 0.5 mL DPBS, and count cells.
Cell Counting of COVID Samples (10x)
Cell Counting of COVID Samples (10x)
Add 0.05 mL sample, 0.05 mL DPBS, and 0.005 mL Solution 13 to a 1.5 mL centrifuge tube, incubate for 00:02:00 at Room temperature.
Add 0.1 mL BD Cytofix Fixation Buffer to the samples and incubate 00:30:00, Room temperature, and protect from light.
Aliquot 0.01 mL sample to the well of a NC-Slide A8 and count on the NC-3000.
Record number and viability below, calculate total cells:
Follow the appropriate 10X protocol (Chromium Next GEM Single Cell 3’ Reagent Kits v3.1 User Guide – Rev D) for encapsulation of cells from the airway sample.