Sequencing Technologies 



Application of flow cytometry to DNA sequencing. The small yellow spot In 

 the center of this multiple-exposure photograph shows the fluorescence from 

 approximately 1 000 molecules of the laser dye — rhodamine 6G. The apparatus 

 shown is a modified flow cytometer with the green argon laser beam traversing 

 from left to right: the flow cuvette is vertical in the center. The fluorescence 

 collection lens can be seen in the background. An apparatus similar to the one 

 shown in the photograph is being developed to sequence DNA by detection of 

 single, fluorescent molecules. (Photograph provided by James Jett, Los Alamos 

 National Laboratory.) 



12 



