I have isolated PBMC cell subtypes(but never monocytes) from platelet aphaeresis products(in my case TRIMA filters). It should be possible . I isolated PBMCs from my aphaeresis source and then isolated my cell subtype from the PBMCs. You will need to optimize your dilution step for Ficoll Paque isolation; in my applications I got ~10ml of TRIMA filter aphaeresis solution then diluted 1:2 in PBS followed by Ficoll Paque. I had to RBC lyse after isolation to clean up the sample.

If you have a very large starting volume see if you concentrate all the cells and then optimize how much you dilute it from there to get the best yields. You can then cryopreserve your PBMCs and to avoid doing this process over and over again. You should also characterize this cell source via Flow prior to use so you can compare your monocyte isolation method to your PBMCs.

For pure monocytes there are numerous commercial kits(they can be expansive though) that can isolate monocytes from a variety of cell sources see examples below. Pay attention to positive vs negative selection as they can affect downstream applications:

https://www.stemcell.com/easysep-human-monocyte-isolation-kit.html

https://www.miltenyibiotec.com/US-en/products/macs-cell-separation/cell-separation-reagents/microbeads-and-isolation-kits/monocytes-and-macrophages/classical-monocyte-isolation-kit-human.html

https://www.miltenyibiotec.com/US-en/products/macs-cell-separation/cell-separation-reagents/microbeads-and-isolation-kits/monocytes-and-macrophages/pan-monocyte-isolation-kit-human.html

For cheaper options I know people have done monocyte separation from PBMCs via plastic adherence good success. There are lots of protocol available online for this isolation method.

Dear you can isolate the cells by cell sorting using flowcytometry.

Hi Christian

There is a cheeky way to collect white cells including monocytes from platelet apheresis sample. If you have a leucocyte depletion filter for platelets, put the apheresis sample through it and then flush the white cells out from the filter using saline. You could then do ficol sedimentation to get the mononuclear cells. Good luck.

Siva

William Suslovic do you use leukocyte reduction filters? Are TRIMA filters the same thing? It is the first time that I'm doing an experimental project so I do not many terms or procedures like apheresis. I understand that this technique is used to separate blood components but how apheresis machines separate WBCs? do they have an incorporated filters or you have to put them?

Muttuswamy Sivakumaran do you mean after apheresis I should put the collection in other filter or can I put the filter in the apheresis machine? I do not have experience in experimentals projects or procedures like apheresis. Also, do you have a protocol about WBCs extraction from the filters? or can you mention the steps for fdoing that, please?

No, you should use a leucocyte depletion filter that is designed to remove white cells from pooled platelets. You could use a Pall filter or something similar. There are quite few on the market. If you cannot get hold of one, then you could try a Nucleopore filter (or something similar) with a pore size of more than 3 microns to let the platelets go through and retain the white cells on the surface. You can then collect the cells by just rinsing with saline. Remember, the cell pellet will contain all white cell subsets (neutrophils, lymphocytes and monocytes. Good luck. Siva