we describe methods and apparatus for high - speed high - contrast imaging one -, two - and three - dimensional imaging enabled by differential interference contrast time encoded amplified microscopy of transparent media without the need for chemical staining , that are suitable for a broad range of applications from semiconductor process monitoring to blood screening . our methods and apparatus build on a unique combination of serial time - encoded amplified microscopy and differential interference contrast microscopy . these methods and apparatus are ideally suited for identification of rare diseased cells in a large population of healthy cells and have the potential to revolutionize blood analysis and pathology including identification of cancer cells , such as circulating tumor cells in early stage disease .