Our results pave the way to study heterogeneous systems locally in a previously impossible manner.

We propose this tiered experimental approach as a paradigm to unravel gene expression in other cellularly heterogeneous systems.

Unambiguous assignment of these heterogeneous systems will rely heavily upon further enhancements in both data analysis protocols and instrumental resolution.

These experiments illustrate the limitations of using a gross descriptor of preferential solvation to describe solute partitioning into complex, heterogeneous systems having nanometer-scale dimensions.