Oger J, Arnason B G, Pantazis N, Lehrich J, Young M
Proc Natl Acad Sci U S A. 1974 Apr;71(4):1554-8. doi: 10.1073/pnas.71.4.1554.
Mouse submaxillary gland nerve growth factor (NGF) has been covalently joined to bacteriophage and the resulting phage conjugates remain biologically active in stimulating neurite extension from sensory ganglia. A sensitive bacteriophage immunoassay has been developed to measure concentrations of NGF as low as 1 ng/ml. With this method, we find that mouse L and 3T3 cells in culture produce a biologically active nerve growth factor that is immunologically similar if not identical to mouse submaxillary gland NGF. Since L cells are known to be a source of "conditioned medium" for tissue culture, it could be that one or more of the conditioning factor activities secreted by these cells are due to NGF itself.
小鼠颌下腺神经生长因子（NGF）已与噬菌体共价结合，所得噬菌体缀合物在刺激感觉神经节的神经突延伸方面仍具有生物活性。已开发出一种灵敏的噬菌体免疫测定法来测量低至1 ng/ml的NGF浓度。用这种方法，我们发现培养中的小鼠L细胞和3T3细胞产生一种生物活性神经生长因子，其在免疫学上即使不与小鼠颌下腺NGF完全相同也极为相似。由于已知L细胞是组织培养“条件培养基”的来源，这些细胞分泌的一种或多种条件因子活性可能是由于NGF本身。
