Fig. 3.

ROR1⁺ cell aggregation leads to transparent and light-focusing micro-lenses. (A-Q) Light microscopy data from ROR1⁺-cell aggregates and the maximal focal point below them. After 3 days of culture, the aggregates transmitted less light than the surrounding culture medium (A) and did not focus light (B). As culture progressed, the aggregates transmitted more light (C, day 7; E, day 14) and began focusing light (D, day 7; F, day 14). More-detailed characterisation of a single aggregate shows it had limited transparency (G) and focusing ability (I,K,M,O) on day 3 of culture, but by day 27 it transmitted the same amount of light as the surrounding culture medium (H) and had developed significant focusing ability (J,L,N,P). Quantification of the light transmittance and focusing ability confirms these findings (Q). Scale bar: 40 µm. The images are representative of five micro-lenses from two biological replicates; data in Q are mean±s.e.m.