peripheral blood mononuclear cells (pbmcs) purification using a high throughput automated bead-based method

High-Throughput PBMC Isolation Using Immunomagnetic Beads

Peripheral blood mononuclear cell (PBMC) isolation is a technique that separates and isolates lymphocytes and monocytes from other whole blood constituents. PBMCs are a versatile cell type used for numerous applications including, but not limited to, immunotherapy, vaccine development, target or biomarker identification, and antibody/small molecule drug development1,2. These cells may be isolated from healthy or diseased individuals and can be used immediately in downstream processes or cryopreserved for future research3. In some instances, the downstream purpose is known, while in others, as is common in biobanking, PBMCs are isolated and stored for future unspecified applications4.
Density gradient centrifugation is the traditional technique for isolating PBMCs5,6,7 from whole blood, utilizing the differential separation of the constituent cell types based on cell density during centrifugation. While there may be some variation in this method, whole blood is generally diluted with phosphate-buffered saline (PBS), layered over a density gradient medium in a specialized or standard centrifuge tube, and then spun. Four distinct layers result: the top plasma layer is enriched with platelets, a thin PBMC layer is above the density gradient medium, and finally, the bottom layer consists of red blood cells (RBCs) and granulocytes. Although this method has previously been termed &#39;the gold standard&#39;8, there are limitations for scale-up, such as lengthy processing time, centrifuge capacity, difficulty in aliquoting other blood products (i.e., plasma and RBCs), and being laborious to automate. While automation is possible for this method9, it does require comprehensive programming of a liquid handler (with a centrifugation module to be fully automated) and would remain a lengthy process.
Henceforth, an alternate workflow that uses immunomagnetic bead separation with either an eight-holder magnet for manual processing or an instrument for fully automated processing is presented. This method utilizes an antibody cocktail that is added to cells and binds unwanted cell populations, in this case, platelets, granulocytes, and RBCs. These unwanted populations are subsequently removed by magnetic separation, leaving monocyte and lymphocyte populations in the negative fraction that are ready for downstream processing10. This negative selection method is faster than positive selection methods which require additional steps to remove the antibody and magnetic bead complex from the PBMCs. Negative selection is additionally advantageous as it has been described as a way to preserve cell functionality11,12.

Author Spotlight: Advancements in PBMC Isolation &amp;#8211; Enhancing Throughput and Consistency in Research

Isolating Human Peripheral Blood Mononuclear Cells from Buffy Coats via High Throughput Immunomagnetic Bead Separation

Isolating peripheral blood mononuclear cells, also known as PBMCs, is typically a lengthy and manual process. We saw an alternative method that'd be quick to implement and capable of processing high numbers of samples. Our protocol offers an automated high throughput method, ensuring consistency while preventing technician burnout.We also detail our medium throughput automation-compatible method that can be utilized during equipment downtime. This medium throughput option is a more budget-friendly alternative for other laboratories. A biobank can now process more samples with the same number of technicians.This will increase the specimen collection size as well as its diversity, enabling future research and improving patient care.

Peripheral Blood Mononuclear Cells (PBMCs) Purification Using a High Throughput Automated Bead-Based Method

To begin, label two 14-milliliter tubes as A and B, one 15-milliliter centrifuge tube as C, and one 15-milliliter centrifuge tube as waste. After centrifuging the whole blood, collect and add one milliliter of the prepared buffy coat to tube A.Add 60 microliters of 0.1 molar EDTA to tube A.Then vortex the magnetic bead tube for 30 seconds. To turn on the automated PBMC instrument, switch the power on at the front of the instrument.On the instrument's home screen, select profile and choose the desired protocol. Then enter the starting volume and repeat for each sample. Select all the quadrants that will use the same reagent kit.Next, load labeled consumables, filter tips, and buffer container into each quadrant of the instrument's carousel as directed on the automated PBMC instrument screen. Once loading is complete, remove lids from consumables and reagents and select run on the instrument screen. When the run is complete, select unload and remove samples from the instrument's carousel.Transfer 500 microliters of the cells to a sample cup for a no-dilution cell count. Comparing the automated bead-based method to the manual method, no significant differences were identified in cell viability or total cell counts. The manual method processed eight samples in 43 minutes while the automated method took 57 minutes, including 35 minutes of hands-off processing.Mean cell viability was greater than 90%for PBMCs processed within five days and greater than 75%for those processed within 10 days. Mean PBMC yields decreased by 50%after five days compared to specimens processed within 24 hours.

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Research

JoVE Journal

Biology

361 Views. To begin, label two 14-milliliter tubes as A and B, one 15-milliliter centrifuge tube as C, and one 15-milliliter centrifuge tube as waste. After centrifuging the whole blood, collect and add one milliliter of the prepared buffy coat to tube A.Add 60 microliters of 0.1 molar EDTA to tube A.Then vortex the magnetic bead tube for 30 seconds. To turn on the automated PBMC instrument, switch the power on at the front of the instrument.On the instrument's home screen, select profile and cho...

Video: Peripheral Blood Mononuclear Cells (PBMCs) Purification Using a High Throughput Automated Bead-Based Method

Peripheral blood mononuclear cells (PBMCs) are a heterogeneous population of monocytes and lymphocytes. Cryopreserved PBMCs have stable viability in long-term storage, making them an ideal cell type for many downstream research purposes, including flow cytometry, immunoassays, and genome sequencing. Typically, PBMCs are isolated via&#160;density gradient centrifugation, however, it is a low-throughput workflow that is difficult and costly to scale. This article presents a high-throughput workflow using a magnetic bead-based PBMC isolation method that is quick to implement. Total cell concentration, viability, and population distribution with PBMCs obtained using density gradient isolation were compared, and cell viability and proportion of cell types were comparable for both techniques. Isolated PBMCs demonstrated over 70% viability up to 9 days after blood collection, although yield decreased by half after 5 days compared to PBMCs processed within 24 h of collection. In summary, this article describes a PBMC protocol that utilizes a bead-based approach to adapt to a high throughput workflow and demonstrates that both manual and automated bead-based methods can increase processing capacity and provide flexibility for various budgets.

This protocol details a high-throughput automation-compatible method to isolate human peripheral blood mononuclear cells for biobanking and other purposes.

Peripheral blood mononuclear cells (PBMCs) are a heterogeneous population of monocytes and lymphocytes. Cryopreserved PBMCs have stable viability in ...

Whole Blood Purification and Peripheral Blood Mononuclear Cells (PBMCs) Isolation Using Manual Method

To begin, gently invert 10-milliliter whole blood tubes 10 times at room temperature. Using a swinging bucket rotor, centrifuge the tubes at 800 g for 10 minutes at 22 degrees Celsius with the brake on. Then place the samples in a biological safety cabinet and check for the three distinct layers.Label three five-milliliter polystyrene tubes with letters A, B, and C.Swirl and collect one milliliter of the buffy coat by aspiration and transfer to the tube labeled as A.Then add 60 microliters of 0.1 molar EDTA to tube A containing the buffy coat. Add 50 microliters of the cocktail mix to tube A.Pipette up and down at least three times to mix it and incubate for five minutes at room temperature. After that, add 890 microliters of PBS to tube A and mixed by pipetting at least three times.Next, vortex the magnetic bead tube for 30 seconds. Add 50 microliters of the magnetic beads to tube A and pipette at least three times to mix the beads thoroughly. Immediately place tube A into the magnet stand and incubate for five minutes at room temperature.Then carefully pipette the enriched cell suspension into tube B, collecting the clear fraction with no or minimal red blood cells for optimal PBMC recovery. After that, remove tube A from the magnet stand and dispose of it. Next, add 50 microliters of magnetic beads to cell suspension in tube B and pipette up and down at least three times.Immediately place tube B into the magnet stand and incubate for five minutes at room temperature. Carefully pipette the enriched cell suspension into tube C, collecting only the clear fraction. Remove tube B from the magnet stand and dispose of it.Then immediately place tube C into the magnet stand and incubate for five minutes at room temperature. Carefully pipette the enriched cell suspension into a labeled centrifuge tube and top up to two milliliters with PBS. Transfer 50 microliters of the cell suspension to a sample cup of the automated cell counter.Add 450 microliters of PBS for a 1 to 10 dilution cell count.