We describe a method of determining a food-to-biomass ratio in an aqueous fluid the method comprising: providing an aqueous fluid comprising viable biomass and food for said biomass, and wherein there is insufficient available food to sustain all said viable biomass; using a sensor (for example a respirometer or a sensor for sensing an amount of ammonia, ammonium, nitrates or nitrites) to determine an amount of food in said aqueous fluid available to said biomass; determining a measure of viable biomass in said aqueous fluid by measuring polarisability of viable biomass cells in an AC electric field; and determining a food-to-biomass ratio from said amount of food and said measure of viable biomass.

The invention provides a device for growing cells—referred to as a cassette. The cell culturing device includes a housing that contains a lid having an optically clear window; a fluid distribution channel; a sample injection port fluidically connected to the fluid distribution channel; a base housing a porous media pad; and a media injection port fluidically connected to the media pad. The lid mates to the base to form a sterile seal; the fluid distribution channel is disposed over the media pad, which is viewable through the optical window; and sample fluid introduced into the fluid distribution channel is distributed evenly to the media pad, e.g., via a plurality of channels. The invention also provides kits that include cassettes of the invention and a tube set.

The present disclosure provides a device that includes a base comprising a substrate having a first major surface, a pressure sensitive adhesive adhered to at least a portion of the first major surface, a polymeric cover film coupled to the substrate via the adhesive, a plurality of isolated closed compartments disposed between the substrate and the cover film, and an aqueous liquid disposed in two or more of the closed compartments. The cover film is a composite film comprising ethylene vinyl acetate copolymer, a linear copolymer of ethylene and a higher alkene, and a tackifier. Each compartment of the plurality is defined by a seal that prevents liquid communication with at least one other compartment of the plurality. Methods of using the device for partitioning a sample, for analyzing a sample, and for culturing a microorganism are also provided.

A system and method with increased sensitivity to microorganism growth. The system includes signal processing electronic circuit connected to a consumable or vessel through two or more electrodes that fully penetrate the vessel and are in contact with the fluid contents. The electronic circuit is configured to detect a component of the total impedance of the sample, specifically the “out-of-phase” or imaginary reactance component, which has a sensitive response to organism growth in a frequency-dependent manner. The system detects changes in both the composition of charged molecules in the liquid matrix and the number of microorganisms based on monitoring the sample for change in this parameter. This results in a 5-70% reduction in time-to-detection (TTD). The system and method detect organisms in a plurality of vessel shapes, volumes, and matrix (or media) formats. The electrodes are fully immersed in a continuous body of liquid sample. The distance between electrodes may be adjusted or tuned to fit the needs of the vessel. The voltage inputs can also be adjusted to allow proper detection of the contents within the vessel.

There is provided a cell culture evaluation system, a cell culture evaluation method, and a cell culture evaluation program which are capable of estimating and evaluating the lag time or the minimum doubling time and objectively and adequately determining whether or not a cell population is stimulated for proliferation by using an average projected area of a cultured cell population or the rate of increasing the ratio of the non-single-cells as an evaluation parameter when culturing the cells. Images of the cell population to be cultured statically are acquired in a culture vessel, the average projected areas of the cells are calculated from the images for the respective culture times, and the lag times at lag phase are calculated from the calculated average projected areas of the cells. The single-cells and the non-single-cells are discriminated from the images, and the increasing rate of the non-single-cells is calculated from the ratio of the non-single-cells in the cell population to determine the minimum doubling time from the increasing rate of the non-single-cells. Whether or not the cell population is stimulated for proliferation is determined from the ratio of the non-single-cells.

A detector arrangement for a blood culture bottle incorporating a colorimetric sensor which is subject to change of color due to change in pH or CO.sub.2 of a sample medium within the blood culture bottle. The detector arrangement includes a sensor LED illuminating the colorimetric sensor, a reference LED illuminating the colorimetric sensor, a control circuit for selectively and alternately activating the sensor LED and the reference LED, and a photodetector. The photodetector measures reflectance from the colorimetric sensor during the selective and alternating illumination of the colorimetric sensor with the sensor LED and the reference LED and generates intensity signals. The reference LED is selected to have a peak wavelength of illumination such that the intensity signals of the photodetector from illumination by the reference LED are not substantially affected by changes in the color of the colorimetric sensor.

A device (10) for detecting the presence of at least one microorganism in the contents (101, 201) of a container (100, 200) comprising a wall with a translucent zone, said detection device (10) comprising: a) at least one light source (11), such as a light-emitting diode (LED), capable of illuminating the contents of the container (100, 200) by emitting an excitation light beam through the translucent zone of the container (100, 200); b) at least one detection means (12, 13, 14, 15), such as a photodiode, for detecting at least one reaction light beam emitted in response to the illumination of the contents (101, 201) of the container (100, 200);
said at least one light source (11) and said at least one detection means (12, 13, 14, 15) being equipped with at least one connection means (105, 205), to connect said at least one light source (11) and said at least one detection means (12, 13, 14, 15) to the wall of the container (100, 200), in the translucent zone, said at least one detection means (12, 13, 14, 15) being positioned at an angle of a set value in relation to the direction of the excitation light beam, to detect the reaction light beam.

The invention relates to a bioreactor comprising a tank (100) capable of being operated for a working period, said tank (100) being intended to receive a culture medium comprising a cellular culture of photosynthetic microorganisms, a light source (200) arranged to emit incident light having a chosen incoming light intensity (Iin) in the direction of the tank, a temperature probe (400) for measuring the temperature of said culture medium in the tank, and a temperature regulator (500) capable of raising and lowering the temperature of said culture medium in the tank, and further comprising a control (700) of the temperature regulator arranged to adjust the temperature of the culture medium to a low setpoint value (VCB) during a first period, and to adjust the temperature of the culture medium to a high setpoint value (VCH) during a second period, the succession of said first and second periods making it possible to induce a cellular stress in at least some of said photosynthetic microorganisms during the working period.

High throughput cultivation systems are used in pharmaceutical research and development. In this connection, samples are taken and analyzed for important parameters using external analysis. The results of the analysis serve to assess the cultivation process and provide important information about the process. Especially with cultivations carried out in parallel, the manual effort of sample preparation is great and can lead to errors. In order to avoid the need for sampling and thus to minimize the errors, a method is described in the present patent application which makes desired target parameters accessible in the form of soft sensors by means of previously recorded process variables. Herein is described a method for determining process-relevant parameters in CHO processes (Chinese hamster ovary) in high-throughput cultivations, in particular glucose, lactate and the live cell density or the live cell volume.

The present disclosure provides a culture device for enumerating colonies of sulfate-reducing microorganisms. The device includes a body having a waterproof base, a waterproof coversheet attached to the base, and a growth compartment disposed therebetween. The growth compartment has a perimeter and an opening. A portion of the perimeter is defined by a waterproof seal. The portion can include >50% of the perimeter. Disposed in the growth compartment are a dry cold water-soluble gelling agent, a dry culture medium selected to facilitate growth of a sulfate-reducing bacterium or indicator reagent for detecting hydrogen sulfide production by a sulfate-reducing bacterium, and a dry first oxygen-scavenging reagent.