This paper reports the thermal conductivity k of matched pair cell lines: two pairs of a normal and a cancer cell, one pair of a primary and metastatic cell. The 3ω method with a nanoscale thermal sensor was used to measure k at the single-cell level. To observe the difference in k between normal and cancer cells, the measurements were conducted for Hs 578Bst/Hs 578 T (human breast cells) and TE 353.Sk/TE 354.T (human skin cells). Then k of WM-115/WM-266-4, a primary and metastatic pair of human skin cell, was measured to find the effect of disease progression on k. The measured k data for normal and disease cell samples show statistically meaningful differences. In all cases, k decreased as the disease progressed. This work shows that thermal-analysis schemes, such as the 3ω method, have a potential to detect diseases at the cell level.

We demonstrate a strong correlation between denaturation of bovine serum albumin (BSA) and the thermal conductivity k of aqueous solutions of BSA. When denaturation of BSA began, k dropped significantly. These results suggest that k, i.e., the ability of a protein to transport passively applied thermal energy, can be exploited to probe the conformational dynamics of BSA and potentially of other proteins. The technique of protein analysis demonstrated in this work is expected to be useful in micro-total-analysis systems because it is easier to miniaturize and to integrate into a device than is conventional differential scanning calorimetry analysis.