Properties of M13 Vectors - M13 genome has been used to produce M13mp series of vectors, e.g., M13mp 8, M13mp 9, etc. The desirable features of M13 vectors are as follows:
(1) very large inserts can be cloned since packaging does not depend on genome size (as is the case with λ vectors).
(2) Pure single-strand copies of double-strand DNA inserts are obtained in abundance.
(3) Since DNA inserts are accepted in either of the orientations (which is also the case for plasmid and λ vectors), some recombinant clones will produce single-strand copies of one strand of the DNA double-strand, while others would produce copies of the complementary strand of the DNA insert.