The impact of semiconductor nanocrystals (quantum dots; Qdots) is felt not only in diverse imaging modalities such as fluorescence microscopy, cytometry, and fluorescence resonance energy transfer (FRET), but also in conventional histological analysis. Among the many advantages of Qdots are their inherent brightness and sensitivity, resistance to photo bleaching, and their narrow emission bandwidth making them ideally suited for multiplexing. The utility of Qdots in clinical settings has been recently documented. In one scenario, Chattopadhyay and co‐workers reported using a cytometric panel of 17 color marker analysis by combining Qdots with conventional tagged antibodies without the need for spectral compensation, yielding new phenotypic differences between the T cell populations of HIV positive individuals. In another study, Schwock and co‐workers used Qdots with laser scanning cytometry for the assessment of STAT3 and NFKB phosphorylation status in fine needle biopsies of solid tumor xenografts. Their study underscores the clinical utility of fine needle sampling of solid tumors for biomarker analysis using Qdots in anatomic sites where core‐needle biopsies are not possible or not well tolerated. Chattopadhyay et al., Nat Med 2006; 12:971–977. Schwock et al., Diagn Mol Pathol 2007;16:130–140.