Figure 1.

Individualized MCF7 single cell seeding on collagen I islands leads to tumor formation. a Steps followed to achieve single cell culture on collagen I islands: (i–iii) Islands of collagen matrix are formed on a culture dish and soaked in culture medium. (iv–vi) Each island is seeded with a single cell while the islands are partially submerged in culture medium. (vii) After cell adhesion, the dish is filled with culture medium to completely submerge the islands. (viii) Islands are incubated in culture medium for 9–10 days to allow single cells to form tumors. b Hemispherical islands (n = 40) of collagen I matrix on a polystyrene culture dish, where each island will receive exactly one single cell for culture. c Microfluidic setup assembled in-house for deterministic single cell picking and placement, with an inset that shows a zoomed in portion of the setup with focus on the glass tip. d Tumors developed from single MCF-7 cells, visualized using bright-field microscopy as well as Hoechst-based fluorescence microscopy after 10 days of culture (tumors are outlined in red using Microsoft EXCEL).