Abstract: A bacteriophage directional cloning vector containing a multiple cloning site, a method for preparing cDNAs that can be cloned in a unique orientation and a bifunctional oligodeoxynucleotide linker, which creates a unique restriction site when ligated to the 3' end of cDNA fragments. The simple and efficient cDNA cloning system reduces the amount of RNA and effort required for the preparation of large directionally cloned libraries by providing a unique vector that accepts cDNA fragments in a unique 5'-3' orientation and by providing a unique bifunctional linker that facilitates the preparation of cDNA fragments that can be ligated directionally into the vector.

Abstract: Methods and compositions are provided for the production of gene mutations and protein analogs using synthetic gene design and double-stranded synthetic oligonucleotide cassettes. The disclosure provides synthetic structural genes, synthetic double-stranded oligonucleotide cassettes and methods for the creation of synthetic gene analogs and polypeptide analogs by shortening or altering the native amino acid sequence.