Abstract: A method of detecting endothelial progenitor cells is provided. The method involves contacting a population of cells with a composition comprising a conjugate or complex of the formula Ab-X where the group Ab comprises a folate that binds to endothelial progenitor cells, and the group X comprises a fluorescent chromophore, and eliciting a fluorescent response from bound Ab-X.

Abstract: The invention relates to a method of treating or diagnosing a disease state worsened by progenitor cells. The method utilizes a composition comprising a conjugate or complex of the general formula Ab-X wherein the group Ab comprises a vitamin, or an analog thereof, that binds to progenitor cells, and when the conjugate is being used for treatment of the disease state, the group X comprises an antigen, a cytotoxin, or a compound capable of altering progenitor cell function, and when the conjugate is being used for diagnosing the disease state, the group X comprises a quantifiable marker.