Provided are improved compositions and methods that are used for identifying interacting zinc fingers in a zinc finger and DNA sequence context. The compositions and methods provide a comprehensive approach that takes into account the effect of adjacent zinc fingers, in part by expanding the repertoire of F2 fingers that are varied at amino acid position 6.

Provided are improved compositions and methods that are used for identifying interacting zinc fingers in a zinc finger and DNA sequence context. The compositions and methods provide a comprehensive approach that takes into account the effect of adjacent zinc fingers, in part by expanding the repertoire of F2 fingers that are varied at amino acid position 6.

An autoinducer-2 (AI-2) molecular response-based starting element and an Escherichia coli (E. coli) dynamic regulation system and method constructed thereby are provided. A cell density-dependent starting element P.sub.J23119-LsrR-P.sub.lsrA based on an AI-2 molecular response is constructed. The element can be used to self-induce the expression of dCpf1, and crRNAs of different target genes are further assembled, such that the self-inducible element can be used for dCpf1-CRP to achieve the dynamic regulation of genes in a synthesis pathway. In the present disclosure, vectors pACYDuet-P.sub.J23119-LsrR-P.sub.lsrA-dCpf1-CRP, pRSFDuet-GFP-mCherry, and pETDuet-crRNA can be constructed to simultaneously achieve the transcriptional activation and inhibition of different genes. The construction method of recombinant E. coli in the present disclosure is simple and has promising application prospects.

The invention provides a genetically modified micro-organism for intracellular biosynthesis of a cellular metabolite, comprising a synthetic error correction system having a penalty gene, whose expression leads to arrested growth or cell death (e.g. a toxin gene) in combination with a survival gene, whose expression provides an antidote that restores cell viability and normal growth (e.g. a cognate antitoxin gene). Alternatively, the system has a survival gene, alone, whose expression is essential for growth (i.e. essential gene). The synthetic error correction system further comprises a biosensor, whose function is to induce expression of the survival gene which leads to cell growth, only, when the cell produces a pre-defined level of a given metabolite. The invention further encompasses: a method for producing the genetically modified micro-organism; a method for producing a cellular metabolite with the genetically modified micro-organism; and use of the genetically modified micro-organism for producing a cellular metabolite.

A method for selecting genome edited cells and/or for enrichment of genome edited cells in a population of cells comprising: (a) introducing into a cell or a population of cells at least one first component, at least one second component and at least one third component; and (b) selecting the genome edited cells which transiently express or transiently upregulate a nucleotide sequence encoding a selector.

The invention provides methods and compositions useful for identifying polypeptides with desired characteristics in vitro.

The present invention provides novel microfluidic substrates and methods that are useful for performing biological, chemical and diagnostic assays. The substrates can include a plurality of electrically addressable, channel bearing fluidic modules integrally arranged such that a continuous channel is provided for flow of immiscible fluids.

Methods and materials for identification of compounds that allow translation read-through of nonsense mutations in recombinant microorganisms and mammalian cells.

The present invention provides a method and components thereof of performing genetic modification under a drug-free environment. The method comprises the steps of generating a trapped mammalian cell library by trapper constructs (including the element of piggyBac terminal inverted repeats (TIRs)), reporter constructs, and helper constructs (including a sequence of an internal ribosomal entry site (IRES)). The present art allows: (1) to target & identify the silenced loci; (2) to separate genes with low-level expression at certain differentiation stages; (3) to evaluate the efficiency of gene targeting in the silent or repressed loci. The present invention avoids the biased gene targeting observed in the prior arts, and eliminates the needs of introducing antibiotic genes into the host genome which may lead to a potential threat of drifting antibiotic resistant genes into environment.

The invention refers to a library of bidirectional expression cassettes or expression vectors comprising a repertoire of bidirectional promoter sequences, each expression cassette comprising a promoter sequence operably linked to a first gene in one direction, and operably linked to an oppositely oriented second gene in the other direction which is different from the first gene, and bidirectional Pichia pastoris or CHO cells promoter sequences. The invention further refers to a method of screening or selecting a bidirectional promoter suitable for expressing at least two GOI in a host cell and a kit comprising a) an expression cassette consisting of the first and second genes and a stuffer sequence separating them, which stuffer sequence comprises a recognition site for a type IIS restriction enzyme at both ends; b) the type IIS restriction enzyme; c) and a repertoire of promoter, preferably a promoter library including bidirectional promoters.