Abstract: An isolated recombinant luciferase having luciferase activity. The recombinant luciferase has an amino acid sequence which differs from the wild-type luciferase from Phtotinus pyralis, Luciola mingrelica, Luciola cruciata, Luciola lateralis, Hotaria parvula, Pyrophorus plagiophthalamus, Lampyris noctiluca, Pyrocoelia miyako or Photinus pennsylvanica. In the seguence of the recombinant luciferase, the amino acid residue corresponding to phenylalanine 295 in Photinus pyralis wild-type luciferase or to leucine 297 in Luciola mingrelica, Luciola cruciata or Luciola lateralis wild-type luciferases, is mutated compared to the corresponding amino acid which appears in the corresponding wild-type luciferase sequence. The recombinant luciferase has increased thermostability compared to the corresponding wild-type luciferase.

Abstract: An isolated recombinant luciferase having luciferase activity. The recombinant luciferase has an amino acid sequence which differs from the wild-type luciferase from Photinus pyralis, Luciola mingrelica, Luciola cruciata, Luciola lateralis, Hotaria parvula, Pyrophorus plagiophthalamus, Lampyris noctiluca, Pyrocoelia miyako or Photinus pennsylvanica. In the sequence of the recombinant luciferase, the amino acid residue corresponding to phenylalanine 295 in Photinus pyralis wild-type luciferase or to leucine 297 in Luciola mingrelica, Luciola cruciata or Luciola lateralis wild-type luciferases, is mutated compared to the corresponding amino acid which appears in the corresponding wild-type luciferase sequence. The recombinant luciferase has increased thermostability compared to the corresponding wild-type luciferase.

Abstract: An isolated recombinant luciferase having luciferase activity. The recombinant luciferase has an amino acid sequence which differs from the wild-type luciferase from Photinus pyralis, Luciola mingrelica, Luciola cruciata, Luciola lateralis, Hotaria parvula, Pyrophorus plagiophthalamus, Lampyris noctiluca, Pyrocoelia miyako or Photinus pennsylvanica. In the sequence of the recombinant luciferase, the amino acid residue corresponding to phenylalanine 295 in Photinus pyralis wild-type luciferase or to leucine 297 in Luciola mingrelica, Luciola cruciata or Luciola lateralis wild-type luciferases, is mutated compared to the corresponding amino acid which appears in the corresponding wild-type luciferase sequence. The recombinant luciferase has increased thermostability compared to the corresponding wild-type luciferase.

Abstract: An isolated recombinant luciferase having luciferase activity. The recombinant luciferase has an amino acid sequence which differs from the wild-type luciferase from Photinus pyralis, Luciola mingrelica, Luciola cruciata, Luciola lateralis, Hotaria parvula, Pyrophorus plagiophthalamus, Lampyris noctiluca, Pyrocoelia miyako or Photinus pennsylvanica. In the sequence of the recombinant luciferase, the amino acid residue corresponding to phenylalanine 295 in Photinus pyralis wild-type luciferase or to leucine 297 in Luciola mingrelica, Luciola cruciata or Luciola lateralis wild-type luciferases, is mutated compared to the corresponding amino acid which appears in the corresponding wild-type luciferase sequence. The recombinant luciferase has increased thermostability compared to the corresponding wild-type luciferase.

Abstract: A protein having luciferase activity and at least 60% similarity to luciferase from Photinus pyralis, Luciola mingrelica, Luciola cruciata or Luciola lateralis.

Abstract: The use of an assay for adenylate kinase in an in vitro test for the effect of external conditions on the growth characteristics of bacterial cells. Such tests in particular include tests for the sensivity of a bacteria to an antibiotic or a biostatic agent, and tests to assess the growth stage and health of the bacteria. Methods of carrying out these tests and kits for effecting them are also described and claimed.

Abstract: A method for producing a polypeptide product which is substantially free of an undesired protein, the process comprising culturing a host cell which is able to express said polypeptide product and which is able to express said undesired protein only in a mutant form which form has the activity of the corresponding native protein under culture conditions but is unstable under conditions at which the said polypeptide product remains stable; and recovering the desired product, wherein either the host cell culture or the recovered product is subjected for a sufficient period of time to conditions under which the undesired protein is unstable so as to denature the undesired protein The method allows the production of products which are substantially free of particular undesired contaminants.