Figure 2.

Spheroids with encapsulating basement membrane in 3D collagen gels. (A) MCF10A spheroids confined by a basement membrane stained with collagen IV antibody and imaged using a confocal microscope. (B) MDA‐231BO spheroid stained for collagen IV is shown as a confocal slice and a max‐projection of the collagen IV surrounding the 3D spheroid. (C) High‐resolution images of MDA‐231BO spheroids with an intact basement membrane before and after initial break through the basement membrane. (D) Six days after spheroids were incubated in 3D collagen gels, cells migrated into the 3D ECM. Note that the absence of a basement membrane or collagen IV staining is because the cells have broken out and migrated away from the initial spheroid, which is depicted by dashed lines.