Negative selection after live cell barcoding with EasySep

[Giorgio]

Hi all,
we have tried to do EasySep negative selection after Live Cell barcoding (anti-B2M Cd and Pt conjugated abs), but couldn't recover any cells, as if all cells got stuck to the magnetic beads, including the ones we wanted to isolate. Does anybody know whether polymers might get trapped to the beads?
Thanks a lot for your help,
Giorgio

[dahern]

Hi Giorgio,

I think for easysep isolations the depletion cocktail TAC complexes will bind to any antibodies (or any mouse anti-human Ab) that are bound to the cell surface - not just the ones that are in the depletion cocktail.

So, they are binding to all your cells if they are pre-labelled with anti-B2M and depleting them from your sample.

I believe that's how the easysep depletion kits work, but could be wrong.

[jobagins]

Giorgio

I would imagine you simply pull out all cells because of your barcoding with Cadmium - the magnet will pick it all up

[Giorgio]

Hi David, I think you are right, I naively assumed they were anti-biotin beads as the milteny ones, but they are not.
Thanks a lot,
Giorgio

[JamesW]

Giorgio

I would imagine you simply pull out all cells because of your barcoding with Cadmium - the magnet will pick it all up

This is an interesting point, presumably whether it is affected will come down to the exact element and the amount of metal label on the cells. Im not sure about the impact of chloride or nitrate forms.

My understanding is that Cadmium is weakly Diamagnetic (repellant to magnets) so should probably be ok. I have previously run Platinum and Indium barcoded cells through an EasySep magnetic without any problems in terms of purity of the positively selected fraction.