Noninvasive Photoacoustic Microscopy of Living Cells in Two and Three Dimensions through Enhancement by a Metabolite Dye

Abstract
Rich in contrast : A new type of contrast agent, 1‐(4,5‐dimethyl‐2‐thiazolyl)‐3,5‐diphenylformazan (MTT formazan), is reported for nondestructive and nontoxic imaging of living cells by photoacoustic microscopy (see picture). The contrast mechanism is general and can be applied to essentially all types of metabolically active cells, including stem cells and tumor cells.