Abstracts: 



Mapping 



Instrumentation 



Genomic Instrumentation 



Jack B. Davidson 



Instrumentation and Controls Division. Oak Ridge National Laboratory, Oak Ridge. 



TN 37831-6010 



(615) 574-5599. FTS 624-5599 



We are taking a two-level approach to instrumentation needs in DNA mapping and 

 sequencing. On the first level, developments to improve present gel-based techniques 

 are extensions of our approach to filmless autoradiography. Using ultralow-light-level 

 digital television, we detect macromolecules labeled with 'H, "C, "S. or '-P directly 

 from dried gels impregnated with a liquid scintillator or by use of an intensifying 

 screen. Originally developed for two-dimensional protein distributions, the method has 

 improved the speed and accuracy of data acquisition and may be useful for imaging the 

 blots found in gene mapping. Upon resolution and field-coverage improvements, large 

 conventional sequencing gels and the blots used in G. M. Church's multiplexing system 

 could be imaged directly. Because light is the detected entity, the basic system can be 

 applied to gels tagged with fluorescent dyes as well as radioactive labels. A related 

 development is a "lensless" radiation microscope for imaging beta particles in in situ 

 hybridization studies and in neuronography. One goal— to visualize radiolabeled genes 

 on chromosomes— requires a 20- to 50-fold improvement in resolution over present 

 capability. 



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