Price (USD): $220.00


Technical Description

M13KO7d3 is a helper phage engineered for multivalent phage display. M13KO7d3 is a derivative of M13KO7 (1) having a wild-type pIII phenotype which allows efficient bacterial transduction but lacking a functional pIII gene thus driving the display of pIII-fusion proteins expressed by the phagemid on the phage head (2). The use of pIII-defective helper phage has been shown to increase display of scFv by a factor up to 100-fold and more (3-5). This preparation contains enough helper phage to superinfect up to 0.5 L (500 ml) of TG1 culture. Other bacterial strains may require different amounts of M13KO7d3 helper phage. More information can be found here.


  • Phage display.

For research use only; not intended for any animal or human therapeutic or diagnostic use.


M13KO7d3 virions were isolated from the supernatant of infected E. coli TG1 cells with a functional gene III and purified by PEG precipitation.


Composition: 50% glycerol TBS buffered.

Concentration: 1.0 x1013 virions/ml.

Storage temperature: -20°C.

Product size: 0.5 ml.

Quality Control & Certification of Analysis

Virion concentration

Phage DNA concentrations are determined by UV spectrophotometry and virion concentrations calculated based on the length of M13KO7d3 genome.


  1. Vieira, J. and Messing, J. (1987) R. Wu and L. Grossman (Eds.), Methods Enzymol., 153, pp. 3-11. San Diego: Academic Press.
  2. Dueñas, M. AND Borrebaeck CA. (1995). Novel helper phage design: intergenic region affects the assembly of bacteriophages and the size of antibody libraries, FEMS Microbiol lett., 125(2-3):317-21.
  3. Rondot, S., Koch, J., Breitling, F. and Dübel, S. (2001). A helper phage to improve single-chain antibody presentation in phage display. Nat Biotechnol., 19(1):75-8.
  4. Broders O, Breitling F, Dübel S (2003). Hyperphage – Improving antibody presentation in phage display, Methods Mol Biol, 205, 295-302.
  5. Soltes G, Hust M, Ng KKY, Bansal A, Field J, Stewart DIH, Dübel S, Cha S, Wiersma EJ (2007). On the influence of vector design on antibody phage display, J Biotechnol. 127, 626-637.

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