Fig. 3

Doxycycline reduces the invasion of 12Z endometriotic cells in dose dependent manner. a Representative pictures of two matrigel invasion assays: 12Z endometriotic cells were seeded into matrigel-coated invasion chambers and treated with respective doses of doxycycline in serum-free medium. Serum-containing medium (DMEM containing 10% fetal bovine serum) was added to the lower chamber as a chemoattractant and the invasion chambers were incubated for 22 h at 37 °C and 5% CO₂. Subsequently, the invaded cells were fixed, stained with crystal violet and counted using a microscope. The violet-stained endometriotic cells are clearly distinguishable from the much smaller, unstained pores of the matrigel membrane. b Relative number of invaded cells compared to the untreated control. Result of two independent experiments performed in duplicate each. c Control treatment with EDTA which inhibits the activity of gelatinases by binding of zinc. The results are represented as mean ± SD