Isolation of quiescent noncycling CD34⁺ cells (QSCs) and cycling CD34⁺ and CD34⁻ cells from bulk CML CD34⁺ cells after 4 days culture in serum-free media with 5 growth factors. The QSC gate is determined by the CFSE fluorescence of noncycling CD34⁺ cells following treatment with colchicine.