SDS-PAGE analysis of menstrual blood following Hb, Alb and IgG depletion. Coomassie-stained 15% SDS-PAGE gel of S2 menstrual blood as well as samples depleted of Hb, Alb and IgG. Lane 1, whole menstrual blood; Lane 2, Hb-depleted menstrual blood (Ni-agarose flow through); Lane 3, Hb fraction eluted from Ni-agarose beads; Lane 4, Hb and IgG/Alb depleted menstrual blood (ProteoPrep Immunoaffinity column flow through); Lane 5, IgG and Alb ProteoPrep Immunoaffinity column elute. M = molecular weight markers. 50 μg protein loaded/lane. Hb ∼17 kDa, Alb ∼66 kDa, IgGH heavy chain ∼50 kDa, IgGL light chain ∼25 kDa.