| Existing ways of labeling and visualizing DNA and protein molecules rely on the light-emitting properties of a limited group of radioactive elements, chemical dyes and protein molecules. These labeling techniques have several drawbacks: radioactive markers have short lifespans, while organic dyes come with a limited number of colors and may quickly lose their glow. There have been great demands for more reliable and more robust labeling fluorophores in biomedical research and applications, so as to enable real-time imaging and quantitative determination of multiple-molecule types present in cells or tissues. Benefits of Using Quantum Dots in DNA Labeling Highly luminescent quantum dots potentially can overcome the functional limitations encountered with chemical and organic dyes. They are highly stable against photobleaching and have narrow, symmetric emission spectra. In particular, the emission wavelength of quantum dots can be continuously tuned by changing the particle size or composition, and a single light source can be used for simultaneous excitation of all different-colored dots. These novel optical properties can render quantum dots ideal fluorophores for sensitive, multicolor, and multiplexing applications in molecular biology and bioengineering. Using a Confocal Micro-Spectrophotometer to Identify Genes and Proteins Linked to Diseases In order to understand the complexity and dynamic interactions of biological molecules, it is desirable to monitor and visualize the interactions of multiple proteins or DNA sequences present in cells or tissues. A new strategy will be developed for quantitatively imaging the biochemical contents in organisms. For example, diverse receptors or ligands on cells can be simultaneously screened and quantitatively analyzed by using a confocal micro-spectrophotometer. This could provide a direct approach to identify sets of genes and proteins that correlate with certain diseases. | 
