Fig. 1.
Spheroid characterization. a Spheroid size. Asterisk indicates significant difference. b Spheroid circularity as measured by Fiji (ImageJ) software [33]. Circularity is a measure of the fit of the measured shape to that of a circle, calculated as 4π(area/perimeter2). A value of 1.0 indicates a perfect circle whereas approaching 0 indicates an elongated polygon. Asterisk indicates significant difference. ANOVA p-values <0.05. Error bars show standard error of the mean. c & d Representative confocal images of MDA-MB-231 (c) and MCF10A (d) spheroids directly after incorporation into a collagen-I hydrogel and immunostained for collagen-IV. Right panels represent 5 μm optical sections in the Z dimension. Scale Bar =100 μm