In recent years the use of nanoparticles in medical applications has boomed. This is because the various applications that provide these materials like drug delivery, cancer cell diagnostics and therapeutics [1-5]. Biomedical applications of Quantum Dots (QDs) are focused on molecular imaging and biological sensing due to its optical properties. The size of QDs can be continuously tuned from 2 to 10 nm in diameter, which, after polymer encapsulation, generally increases to 5 – 20 nm diminishing the toxicity. The QDs prepared in our lab have a diameter between 2 to 7 nm. Particles smaller than 5 nm can interact with the cells . Some of the characteristics that distinguish QDs from the commonly used fluorophores are wider range of emission, narrow and more sharply defined emission peak, brighter emission and a higher signal to noise ratio compared with organic dyes . In this paper we will show our progress in the study of the interaction of quantum dots in live cells for image and Raman spectroscopy applications. We will also show the results of the interaction of quantum dots with genomic DNA for diagnostic purposes.