A number of phage vectors are used in DNA and cDNA cloning. Perhaps the most widely used are phage lambda vectors. They are used for the following.

  • cloning of mammalian DNA fragments (genomic DNA libraries)
  • cloning and expression of mammalian cDNAs (cDNA libraries).

Bacteriophages are used for phage therapy for bacterial infections as

  • a single dose of phage should treat an infection (they replicate themselves later)
  • non-toxic
  • highly specific for targeted bacterial populations (unlike antibiotics which also kill normal flora)
  • antibiotic-resistant phage remain sensitive to phage-mediated lysis.

Phage display technology involves the expression of exogenous proteins, peptides or peptide libraries on the surface of bacteriophage. This technology is simple, easy to use, low in cost, safe, and immunogenic (for vaccine studies).

Applications of phage display technology include:

  • Identification of novel peptides with the ability to bind to defined target molecules (e.g., cell surface receptors or enzymes), and human monoclonal antibodies with defined reactivity against specific targets.
  • Use of recombinant bacteriophage displaying antigens from infectious disease agents as candidate vaccines, to confer immune responses against the encodedpeptides or proteins.