Haftmann, Claudia et al. “Direct Uptake of Antagomirs and Efficient Knockdown of miRNA in Primary B and T Lymphocytes.” Journal of Immunological Methods 426 (2015): 128–133. PMC. Web. 3 Nov. 2016.
I have worked with primary cells, monocyte and macrophage from human buffy coat. I advise you to use miRNA mimic and inhibitor of Qiagen. My experience is with this trade mark. The concentration that I have used is 15nM. However, this dependent on your type of miRNA and basal expression level.
In culture plate of 6-well (surface treated for primary culture) added aprox. 150 ul of mix transfection for each well (for all the surface), then 350 ul media and incubation for 6 hours and then to fill until 1ml media for 18 hours more. 24 hours in total of treatment transfection.