PATENT ABSTRACTS 383

employing a hybridization process, which tom- errors, particularly when read with computer- prises: (1) a step of transferring a portion of assisted scanning apparatus. genetic clones cultured on a culture medium onto a filter to fix them thereunto; (2) a step of hybridizing the genes of said clones fixed onto 4870023 said filter with radioactively labeled probes; (3) a step of obtaining two dimensional information R E C O M B I N A N T B A C U L O V I R U S on the location of the radioactively labeled sub- stances on the filter which comprises placing said O C C L U S I O N B O D I E S I N filter having been subjected to the hybridization V A C C I N E S A N D B I O L O G I C A L and a stimulable phosphor sheet in layers for a I N S E C T I C I D E S given period of time to cause said stimulable phosphor sheet to absorb at least a portion of Malcolm J Fraser, Elliot Rosen, Victoria A radiation energy emitted by the radioactively Ploplis assigned to American Biogenetic labeled substances on the filter, exciting said Sciences Inc sheet with an electromagnetic wave to release the radiation energy stored in said sheet as The present invention is directed to recombinant stimulated emission, and detecting the haculoviruses which encode fusion polyhedrin stimulated emission to obtain a locational in- proteins capable of forming occlusion bodies formation on the radioactively labeled sub- containing foreign peptides. The recombinant stances on the filter; and (4) a step recovering the baculoviruses of the invention are formed by in- clones on the culture medium according to the sertion into or replacement of regions of the obtained locational information, polyhedrin gene that are not essential for occlu-

sion body formation, with foreign DNA frag- 4865968 ments by recombinant DNA techniques. The

recombinant occlusion bodies produced in ac- cordance with the present invention have uses in

D N A S E Q U E N C I N G vaccine formulations, immunoassays, im- mobilized enzyme reactions, as biological in-

Leslie E Orgel, James W Patrick assigned to The secticides, and as expression vectors. Salk Institute for Biological Studies

A first mixture is prepared that contains labeled 4880512 chain fragments which each has a common end adjacent to a primary nucleotide and a termina- P U L S E D L I G H T S E L E C T I V E tion at a position from the primary through an nth nucleotide, the first mixture containing P H O T O L Y S I S P R O C E S S F O R nucleotide chain fragments of each length from T R E A T M E N T O F B I O L O G I C A L termination at the primary through termination M E D I A A N D P R O D U C T S M A D E of the nth nucleotide. A second mixture is pre- T H E R E B Y pared that contains labeled chain fragments beginning at the common end and terminating at Paul Cornelius, Robin Hochstrasser, Neville positions from the first through the nth Kallenbach, HarveyRubin, GeorgeJTodaroas- nucleotide, the second mixture containing chain signed to Kollmorgen Corporation fragments of each length terminating wherever either a first or a second of the four nucleotides A novel irradiation process and products made occurs. A third mixture is prepared that contains thereby. The process treats biological media labeled chain fragments beginning at the corn- such as blood fractions, genetically engineered mon end and terminating at a position from the protein products and vaccine preparations. The first through the nth nucleotide, the third mix- process photolyzes nucleic acids in preference to ture containing chain fragments of each length proteins in the media, e.g., it inactivates DNA- terminating wherever the first or a third of the or RNA-containing pathogens while leaving the four nucleotide sequences occurs. The chains are proteins substantially intact or functional. In electrophoresed with the first mixture as the cen- general, the process comprises irradiating the ter lane. This three-lane system provides a uni- medium with pulsed light of wavelength and flux que band pattern fur each of the four nucleotides selected so that (1) the nucleic acids in their and permits the sequence to be read merely by ground state absorb radiation and thereby rise to directly comparing each of the flanking lanes an excited state or states, (2) the nucleic acids in with the fully stepped center lane. This system their excited states absorb radiation and thereby has important advantages in reducing reading rise to higher energy states and undergo photo-