It depends of what are these cells being used for

- CD34+ cells may be easily separated by immunomagnetic isolation (Milteny), a procedure that is accepted by european regulatory agencies (EMA, national agencies, ) if you plan to use them in a clinical trial

- if you plan to expand them you could either first expand and then separate or separate and expand

- streptamer separation is quite good and if you have enough cells do not need further expansion, that means that they will not be conseidered a "cellular medicament"

so, first:

- are these cells from human samples? or come form cryopreserved cord blood? how was cord blod collected?

- do you want to use them in a clinicall trial or to develop some in vitro experiments?

- is there any information that other cell types present (NK, Treg, etc) may interact with your experimental design?

etc

we have two recent papers in PLOS One and Eur J Immunol that may help you

good luck

Best method depends on the purpose of your collection. For biobanking cord blood samples, best separation is done with automated systems. We have used Sepax systems, had very good recovery results.