A gel scanning technique that measures the quench of N-allyl-DANSA fluorescence by amido schwarz stained protein bands had the potential capability of about fifty times the sensitivity of absorption densitometric techniques. The preparation of the fluorescent polyacrylamide gels was straightforward and their electrophoretic resolving and storage properties compared favorably with standard gels. An inexpensive modification of a common commercial fluorometer was described for scanning these gels. © 1969.