[Mutation in the cspH-cspG gene cluster enhances expression of heat-shock proteins and SOS repair system of Escherichia coli].

The recessive radioresistance allele gam12 cloned in plasmid pBC4042-gam12 slightly increases the radiation resistance of Escherichia coli wild-type cells. Meanwhile, irradiation by gamma-rays induces transition of r12 mutation to the homozygous state and causes a 3.37-fold increase in radiation resistance of these cells.

PCR hot start using primers with the structure of molecular beacons (hairpin-like structure).

A new technique of PCR hot start using oligonucleotide primers with a stem-loop structure is developed here. The molecular beacon oligonucleotide structure without any chromophore addition to the ends was used. The 3'-end sequence of the primers was complementary to the target and five or six nucleotides complementary to the 3'-end were added to the 5'-end.

[Hot start of the polymerase chain reaction using DNA helicase].

A novel method for the hot start of PCR using DNA helicases is developed. The addition of a DNA helicase prevents the random annealing of primers and synthesis of nonspecific products during the preparation of the reaction mixture and initial heating. The hot start of PCR occurs automatically after inactivation of the DNA helicase upon heating of the reaction mixture.