Lonza's CD34+ cells should be cultured according to Lonza's "Technical information and Instructions for Culturing Human CD34+ Cells"

Upon thaw, we typically suggest that CD34+ cells be established in culture at a density of 20,000 to 200,000 cells per ml of Lonza’s X-VIVO™ 20 Hematopoietic Growth Medium – 1 L (Lonza Catalog No. 04-448Q) with ITES (or a comparable serum containing medium) and supplemented with cytokines. Without cytokines, the cells will neither proliferate nor differentiate and will survive for approximately 48-72 hours.

Lonza CD34+ cells are not quality control tested for proliferation, and proliferation is not guaranteed under the cell warranty. Expansion of cells may lead to a decrease of CD34+ expression.

For CD34+ cells, the amount of expansion depends on how the cells are stimulated. Since proliferation and differentiation of CD34+ cells are inseparable, if you wish to maintain the "stem cellness" of the CD34 cells, then you must stimulate as little proliferation as possible. If you want the maximum proliferation, you will end up with a population of differentiated cells.

If you are interested in some proliferation but want to maintain as much of the primitive nature of the cells as possible, then it is recommended that you use SCF, TPO, and Flk3/Flt2-Ligand (the amounts that are listed in the literature vary widely, but the average amounts would be 50 ng/ml each).

If you want more proliferation and can tolerate greater differentiation, we would recommend the use of G-CSF, GM-SCF, and SCF (to which many people add IL-3 and IL-6). These can be used at 1 ng/ml, 10 ng/ml, 25 ng/ml, 10 ng/ml, and 10 ng/ml respectively. It is NOT possible, however, to stimulate proliferation in these cells and wind up with more CD34+ cells without a loss in purity (as a result of cellular differentiation).