Abstract: The invention relates to a composition comprising a first modified thermostable enzyme exhibiting 3′exonuclease activity but essentially no DNA polymerase activity and a second modified thermostable enzyme exhibiting DNA polymerase activity, whereas the fidelity of an amplification process is enhanced by the use of the composition in an amplification process in comparison to the use of the single second enzyme in an amplification process and, whereas said first and said second modified thermostable enzyme is reversibly modified by an inhibiting agent which results in essentially complete inactivation of enzyme activity, wherein incubation of said first and said second modified thermostable enzyme in an aqueous buffer at alkaline pH at a temperature less than 25° C. for 20 minutes results in no significant increase in the activity of said first and said second modified thermostable enzyme, wherein incubation at a temperature greater than 50° C.

Abstract: The invention concerns polymerase chimeras which are composed of amino acid fragments representing domains and which combine properties of naturally occurring polymerases that are advantageous with regard to a particular application. It has surprisingly turned out that the domains from the various enzymes are active in the chimeras and exhibit cooperative behaviour. In addition the present invention concerns a process for the production of the chimeras according to the invention and the use of these chimeras for the synthesis of nucleic acids e.g. during a polymerase chain reaction. Moreover the present invention concerns a kit which contains the polymerase chimeras according to the invention.

Abstract: Truncated terminal deoxynucleotidyl transferase (TdT) derivative from calf thymus, characterized in that the derivative in comparison to the native TdT is N-terminally truncated by up to 161 amino acids and has a 20- to 30-fold higher enzyme activity in solutions containing Co2+ ions, and its recombinant production and use.

Abstract: The invention concerns polymerase chimeras which are composed of amino acid fragments representing domains and which combine properties of naturally occurring polymerases that are advantageous with regard to a particular application. It has surprisingly turned out that the domains from the various enzymes are active in the chimeras and exhibit cooperative behavior. In addition the present invention concerns a process for the production of the chimeras according to the invention and the use of these chimeras for the synthesis of nucleic acids e.g. during a polymerase chain reaction. Moreover the present invention concerns a kit which contains the polymerase chimeras according to the invention.

Abstract: The heterologous expression of the reverse transcriptase from the Avian Myeloblastosis Virus (AMV-RT) in prokaryotic cells and in particular Escherichia coli (E. coli) is described in the present invention. The invention also includes certain measures to simplify the purification of the heterodimeric AMV-RT.

Abstract: The present invention relates to thermostable mutants of B-type DNA polymerases comprising a Y-GG/A amino acid motif between the N-terminal 3′-5′-exonuclease domain and the C-terminal polymerase domain whereas the tyrosine of the Y-GG/A amino acid motif is mutated and whereas these mutant DNA polymerases are suitable for PCR.

Abstract: The invention concerns a method for the amplification of nucleic acids using a reagent which prevents reactivation of degradation enzymes. This enables a simpler prevention of contaminations.

Abstract: Thermolabile enzyme with uracil-DNA-glycosylase activity which is in particular characterized by a high degree of purity, short half-lives and a content of contaminating foreign activities of less than 2%, a process for its isolation as well as the use thereof to remove the base uracil from DNA and in particular from PCR products containing uracil. The enzyme is obtainable from gram-positive microorganisms such as e.g. Arthrobacter or Micrococcus.

Abstract: The subject matter of the invention concerns three cosmid vectors which are suitable for fragment cloning of a size between 7 and 36 kb. These vectors consist of an E. coli ColE1 replica, an ampicillin resistance gene, a multiple cloning cassette, cos sites for in vitro packaging with the lambda packaging extracts as well as fragments from the genome of the bacteriophage lambda. The lambda sequences were selected in a way to prevent lytic processes, vector instabilities (deletions) and unwanted recombination events between lambda DNA and the fragment to be cloned. Depending on the length of the lambda fragment inserted in the corresponding vector heterologous fragments of different lengths can be cloned.

Abstract: Enzymes stabilized against the destabilizing effect of ionic surfactants and a method of producing such stabilized enzymes in which DNA sequences which code for the enzymes are modified by directed mutation in defined positions which correlate with defined surface regions of the enzyme, in such a way that the codon in which the mutation is located now codes for an amino acid differing from the original amino acid.