Interrogating cellular nano-architecture may help reveal previously unknown structure-function relations. The three-dimensional mass-density distribution plays an important role in quantifying cellular structure. For instance, chromatin structure can be directly represented by the mass-density, as the individual molecules have similar mass and larger density generally indicates higher level of compaction. Chromatin compaction, in turn, is associated with gene transcription and is crucial in various aspects of fundamental biology, genetics, and oncology studies [1]. Moreover, it has been reported that a statistical representation of mass-density distribution by autocorrelation function (ACF) is crucial in stratifying risk of cancer in early stages [2]. Recent developments such as Partial Wave Spectroscopy [3] have gained success in cancer diagnosis by detecting three-dimensional sub-diffraction chromatin mass-density ACF alterations between malignant cells and healthy cells for various types of cancers.

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