2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/117289In this short report, I briefly review, illustrate and discuss various techniques (e.g., X ray halos, lensing, kinematics) used to derive mass (hence M/L) profiles of individual galaxies.To be published in the Proceedings of the XLIst Rencontres de Moriond, XXVIth Astrophysics Moriond Meeting: "From dark halos to light", Eds. L.Tresse, S. Maurogordato and J. Tran Thanh Van (Editions Frontieres). 10 pages, 6 figures. Updated referencesAstrophysicstext