Immunochemical detection of HS proteoglycan core proteins isolated from hematopoietic progenitor cell lines. Proteoglycans from the human immature erythroid progenitor cell lines TF-1 and HEL and the more mature murine erythroid progenitor cell line ELM-D were treated by heparitinase, submitted to SDS-PAGE on a 4.5% to 15% gradient gel, and subsequently blotted to Biodyne B membrane. Detection was performed using MoAb 3G10 and the ECL-detection system. The MoAb 3G10 recognizes a common neoepitope, generated after heparitinase-digestion of HS proteoglycans.46 This MoAb has been shown to detect most, if not all, HS proteoglycan core proteins after heparitinase-digestion. HS proteoglycans from cervix fibroblasts (cell extract) are shown as positive control (Co, lane 1); supernatant (SN) of TF-1 cells (lane 2), supernatant (lane 3), and cell extract (Ex) (lane 4) of HEL cells; supernatant (lane 5) and cell extract of ELM-D (lane 6). The arrow indicates the HS proteoglycan core protein detected by the MoAb 3G10 in the erythroid progenitor cell lines TF-1, HEL, and ELM-D.