Fig 1: Derivation and characterisation of menstrual flow organoids.a Schematic to illustrate how organoids were derived from an endometrial scratch and menstrual flow in the same cycle. b–d Time line images detailing propagation of organoids from menstrual flow and scratch. b The panel represents the growth of menstrual organoids directly derived from menstrual blood. c, d The panels illustrate the growth of organoids from frozen menstrual (c) and scratch (d) digests of the same patient. Scale bar 400 µm. e Organoids derived from an endometrial scratch and menstrual flow of the same patient are indistinguishable morphologically. Scale bar 200 µm. f, g Single-cell assay to compare the growth of paired menstrual vs. scratch organoids derived from four patients. Images show organoids seeded from single cells (5000 cells per 20 µl drop Matrigel) after 9 days of growth (f). Quantification of the single-cell assay. Scale bar 2000 µm. Five to 8-well repeats were quantified per condition (g). h Representative images of immunostaining against the marker of proliferation, Ki67, in menstrual and scratch organoids of one patient. Scale bar 50 µm. i Quantification of the Ki67 proliferation index in menstrual vs. scratch organoids of three patients.