PRODUCTION OF RECOMBINANT PHAGE

PURPOSE:To select efficiently a recombinant phage, by making transformed Escherichia coli catch a recombinant phage, and causing two point crossing recombination of substitution type between hybrid cell and the infected recombinant. CONSTITUTION:A DNA fragment to code genetic information is inserted into a non-essential gene of phage T4 on a plasmid containing a range of the non- essential gene of phage T4, to form hybrid plasmid. Escherichia coli is transformed by the use of this hybrid plasmid. The transformed Escherichia coli is infected with a recombinant phage wherein a DNA fragment containing a transcription initiation signal and a translation initiation signal is linked to a DNA fragment to code enzyme protein, etc. Consequently, two point crossing recombination of substitution type through homologous properties of DNA is caused, to form a recombinant phage.