When using a phagemid vector, a helper phage (such as M13K07) provides all the necessary gene products for particle formation. They are mutant wild-type bacteriophages that contain the entire genome and have defective replication origin or packaging signals, so the efficiency of self-packaging is low. When infected with Escherichia coli containing phagemids, only the phagemids are effectively packaged for the progeny of the phage produced. Therefore, the obtained phage virus particle contains a mixture of wild-type and fusion coat protein, and the genetic information of the fusion protein is encoded by the packaged phagemid. When using wild-type phage, the interference of plasmids on phage replication will result in a decrease in phage copy number and a sharp drop in virus particle production. Helper phages are designed to overcome interference, maximize virion production, and keep their own ssDNA packaging at a low level.
We provide different quantitative analyses and qualitative analyses for evaluation of produced helper phage according to strict requirements. We know how to avoid phage cross-contamination and how to obtain the maximum number of phage in a single fermentation. Our services are listed below, but not limited to:
M13KO7 Helper Phage is suitable for M13/phagemid hosts and is used to produce ssDNA from vectors containing f1 or f1-like origins of replication
CM13 produces larger plaques and produces twice the cfu/ml in production; therefore, it is easier to prepare.
VCSM13 is a derivative of M13KO7, commonly used for phage display
Hyperphage is an alternative to M13KO7 helper phage for antibody phage display. It allows increasing the display efficiency of antibodies on phage by 2-3 orders of magnitude
R408d3 and KM13 are derivatives of M13KO7, VCSM13 or R408.
The phage DNA concentration is determined by UV spectrophotometry and the virus particle concentration is calculated based on the length of the M13KO7 genome.
The determination of phage titer generally adopts the double-layer agar plate method.
Infectivity is calculated as the ratio between phage titer and virus particle concentration. The infection rate is expected to be greater than or equal to 15%.
Verify the integrity of the phage particle ssDNA by electrophoresis.
The product meets all specifications.
Creative Biolabs can meet the needs of customers by providing helper phage production on time and on budget. We have in-depth knowledge and experience of the tools and processes involved in the phage projects. Our skilled and dedicated scientific researchers ensure that the most suitable methods and techniques are selected for your project. If necessary, please feel free to contact us.
Please kindly note that our services can only be used to support research purposes (Not for clinical use).
Creative Biolabs is a globally recognized phage company. Creative Biolabs is committed to providing researchers with the most reliable service and the most competitive price.
