Abstract: Methods for in situ drug screening are provided which involve culturing a host cell containing two nucleic acid sequences, the first nucleic acid sequence encoding a membrane-permeabilizing agent and the second nucleic acid sequence encoding a desired macromolecule under the operative control of an inducible promoter, to a selected cell density to produce a macromolecule. Thereafter the host cells are exposed to an environmental condition that induces the agent to disrupt the integrity of the cell membrane without complete lysis of the cell membrane, thereby allowing transport through the membrane of small molecular weight compounds. These resulting host cells are provided with a nutrient cocktail containing components that can transport through the disrupted cell membrane, e.g., an inducing agent that induces the tightly regulated promoter and metabolic requirements that permit expression of the macromolecule. Bacterial host cells that can be used in these methods are also provided.

Abstract: A method for recombinantly expressing a macromolecule in a host cell is disclosed which involves culturing a host cell which contains two nucleic acid sequences, i.e., a first nucleic acid sequence encoding a membrane-permeabilizing agent and a second nucleic acid sequence encoding a desired macromolecule under the operative control of an inducible promoter, to a selected cell density that permits accumulation of the agent. Thereafter the host cell is exposed to an environmental condition that induces the agent to disrupt the integrity of the cell membrane without complete lysis of the cell membrane. The host cell thereby allows transport through the membrane of small molecular weight compounds. These resulting host cells are cultured in the presence of a nutrient cocktail that contains components that can transport through the disrupted cell membrane, e.g., an inducing agent that induces the tightly regulated promoter and metabolic requirements that permit expression of the macromolecule.

Abstract: A method for recombinantly expressing a macromolecule in a host cell is disclosed which involves culturing a host cell which contains two nucleic acid sequences, the first encoding a membrane-permeabilizing agent and the second encoding a desired macromolecule under the operative control of an inducible promoter, to a selected cell density that permits accumulation of the agent. Thereafter, the host cell is exposed to environmental conditions that induce the agent to disrupt the integrity of the cell membrane without complete lysis of the cell membrane, which cancels the energized membrane function. The host cell allows transport through the membrane of small molecular weight compounds. These resulting host cells are cultured in the presence of a nutrient cocktail that contains components that can transport through the disrupted cell membrane, e.g., an inducing agent that induces the tightly regulated promoter and metabolic requirements that permit expression of the macromolecule.

Abstract: A method and apparatus involving the configuration of an open capillary channel for size-based separation of analytes is described. The open capillary channel contains numerous turns of defined angles separated by intervening linear or curvilinear segments of capillary tubing. The configuration of the channel allows analyte differentiation based on diffusion coefficients and thus separates analytes by size.

Abstract: A method for recombinantly expressing a macromolecule in a host cell is disclosed which involves culturing a host cell which contains two nucleic acid sequences, i.e., a first nucleic acid sequence encoding a membrane-permeabilizing agent and a second nucleic acid sequence encoding a desired macromolecule under the operative control of an inducible promoter, to a selected cell density that permits accumulation of the agent. Thereafter the host cell is exposed to an environmental condition that induces the agent to disrupt the integrity of the cell membrane without complete lysis of the cell membrane. The host cell thereby allows transport through the membrane of small molecular weight compounds. These resulting host cells are cultured in the presence of a nutrient cocktail that contains components that can transport through the disrupted cell membrane, e.g., an inducing agent that induces the tightly regulated promoter and metabolic requirements that permit expression of the macromolecule.

Abstract: A method for recombinantly expressing a macromolecule in a host cell is disclosed which involves culturing a host cell which contains two nucleic acid sequences, i.e., a first nucleic acid sequence encoding a membrane-permeabilizing agent and a second nucleic acid sequence encoding a desired macromolecule under the operative control of an inducible promoter, to a selected cell density that permits accumulation of the agent. Thereafter the host cell is exposed to an environmental condition that induces the agent to disrupt the integrity of the cell membrane without complete lysis of the cell membrane. The host cell thereby allows transport through the membrane of small molecular weight compounds. These resulting host cells are cultured in the presence of a nutrient cocktail that contains components that can transport through the disrupted cell membrane, e.g., an inducing agent that induces the tightly regulated promoter and metabolic requirements that permit expression of the macromolecule.

Abstract: A method and apparatus involving the configuration of an open capillary channel for size-based separation of analytes is described. The open capillary channel contains numerous turns of defined angles separated by intervening linear or curvilinear segments of capillary tubing. The configuration of the channel allows analyte differentiation based on diffusion coefficients and thus separates analytes by size.

Abstract: A method for recombinantly expressing a macromolecule in a host cell is disclosed which involves culturing a host cell which contains two nucleic acid sequences, i.e., a first nucleic acid sequence encoding a membrane-permeabilizing agent and a second nucleic acid sequence encoding a desired macromolecule under the operative control of an inducible promoter, to a selected cell density that permits accumulation of the agent. Thereafter the host cell is exposed to an environmental condition that induces the agent to disrupt the integrity of the cell membrane without complete lysis of the cell membrane. The host cell thereby allows transport through the membrane of small molecular weight compounds. These resulting host cells are cultured in the presence of a nutrient cocktail that contains components that can transport through the disrupted cell membrane, e.g., an inducing agent that induces the tightly regulated promoter and metabolic requirements that permit expression of the macromolecule.

Abstract: Proteins that cannot be resolved by conventional HPLC techniques, including reversed-phase HPLC, can be distinguished, and the quantity of a protein of interest monitored in numerous types of in-process samples, including fermentation and down-stream processing samples, by covalently binding monobromobimane to a protein of interest bearing sulfhydryl groups and chromatographing these in-process samples using reversed-phase HPLC, fluorescence detection and UV absorbance detection.