利用人類胚胎干細(xì)胞用于治療用途的關(guān)鍵之一是理解幫助干細(xì)胞增殖和分化成其他類型細(xì)胞的分子信號,。如果商業(yè)培養(yǎng)基中的化學(xué)物質(zhì)是私有的（這在科研環(huán)境中很常見），這項(xiàng)任務(wù)就變得更具挑戰(zhàn)性。
目前,，科學(xué)家可能不知道一個培養(yǎng)基中究竟有什么化合物,，這導(dǎo)致了無法預(yù)測的生長行為,，也導(dǎo)致了無法回答哪種成分可能刺激干細(xì)胞,。Peter Andrews及其同事報(bào)告說他們開發(fā)了一種含有肝素的干細(xì)胞培養(yǎng)基，肝素是一種被美國食品和藥品管理局批準(zhǔn)使用的廣為人知的抗凝血劑,。迄今為止,，所有報(bào)告的干細(xì)胞培養(yǎng)基都含有成纖維細(xì)胞生長因子2（FGF-2）和一些實(shí)驗(yàn)室定制的營養(yǎng)物質(zhì)的混合。
這種新開發(fā)的培養(yǎng)基將在沒有FGF-2的情況下支持人類干細(xì)胞,，這可能提供一個標(biāo)準(zhǔn),，能夠?yàn)楦杉?xì)胞如何發(fā)育提供關(guān)鍵的重要信息。只有在這之后科學(xué)家才有能力解釋為什么人類胚胎干細(xì)胞系在不同的實(shí)驗(yàn)室產(chǎn)生了不同的結(jié)果,。（生物谷Bioon.com）
生物谷推薦原始出處：
PNAS Published online before print August 25, 2008, doi: 10.1073/pnas.0806136105
Heparin promotes the growth of human embryonic stem cells in a defined serum-free medium
Miho K. Furue*,?,?, Jie Na?, Jamie P. Jackson?, Tetsuji Okamoto§, Mark Jones?, Duncan Baker?, Ryu-Ichiro Hata‖, Harry D. Moore?, J. Denry Sato**, and Peter W. Andrews
A major limitation in developing applications for the use of human embryonic stem cells (HESCs) is our lack of knowledge of their responses to specific cues that control self-renewal, differentiation, and lineage selection. HESCs are most commonly maintained on inactivated mouse embryonic fibroblast feeders in medium supplemented with FCS, or proprietary replacements such as knockout serum-replacement together with FGF-2. These undefined culture conditions hamper analysis of the mechanisms that control HESC behavior. We have now developed a defined serum-free medium, hESF9, for the culture of HESCs on a type I-collagen substrate without feeders. In contrast to other reported media for the culture of HESCs, this medium has a lower osmolarity (292 mosmol/liter), l-ascorbic acid-2-phosphate (0.1 μg/ml), and heparin. Insulin, transferrin, albumin conjugated with oleic acid, and FGF-2 (10 ng/ml) were the only protein components. Further, we found that HESCs would proliferate in the absence of exogenous FGF-2 if heparin was also present. However, their growth was enhanced by the addition of FGF-2 up to 10 ng/ml although higher concentrations were deleterious in the presence of heparin.
