Fig. 2.

The second harmonic generation (SHG) signal is robust and independent of tissue processing. We obtained comparable images from fresh (a), fixed and Hoechst-stained (b), and paraffin-embedded (c) MCF-7 breast tumor xenograft tissue, consistent with almost identical results obtained by fiber volume (d) and inter-fiber distance quantification (e) of five randomly selected fields of view (FOVs) from each differently processed tissue. Each image size is 339 by 339 μm. The scale bars represent 50 μm.