The trick turns out to be that cancer cells are ''softer'' than healthy cells. Cancer cells need to travel some distances through the body getting by all sorts of obstacles, so they have to be flexible to perform this feat. By using the AFM, the researchers are able to detect this ''softness''.
It seems that this technique could become a useful tool in early cancer detection.
That said, some of the press coverage of this work has been somewhat misleading in that it identifies AFM as a ''new leading edge technology'' .
Twenty-year-old AFM could hardly be called ''new''. Nonetheless, what is interesting about this is that it appears we have just begun to scratch the surface of what the current stable of microscopy tools can achieve.