The present invention relates to hematopoietic cells, and more specifically to methods for long-term in vitro culturing and ex vivo expansion of hematopoietic cells. The present invention also provides compositions useful for culturing cells, such as media for culturing hematopoietic cells, specifically haematopoietic stem cells (HSC) and haematopoietic progenitor cells (HPC). The present invention further provides compositions including growth factor combinations and methods utilizing altered growth and environmental conditions that are applicable in vitro culturing and to ex vivo expansion of HSC and/or HPC.