ResourceGeneral Lab
Determining Lactose Content in Milk Via an Enzymatic Method
14 Apr 2016β-D-galactopyranosyl-(1 -4) D-glucose, more commonly known as lactose, is a disaccharide which constitutes 2 – 8% of milk. In the method in this application note β-galactosidase is added to milk, cleaving lactose into glucose and galactose. At pH 7.8, glucose is phosphorylated by glucokinase, and releases protons that induce a change in pH. The pH change varies as a function of the lactose content of the sample and is measured by using a differential pH analyzer.
Links
Tags
Pipettes and DispensersPipettes and dispensers are essential lab equipment used to dispense measured volumes of liquid accurately. Explore a range of manual and electronic pipettes, including single and multichannel, serological and volumetric pipettes, as well as a range of pipette tips. Bottle-top dispensers are also available for simple and fast solvent dispensing. Find the best pipettes & dispensers in our peer-reviewed product directory: compare products, check customer reviews and receive pricing direct from manufacturers.Sample ManagementSample management systems include sample storage devices such as freezers and plate storers, sample environment enclosures and sample organization, retrieval and sorter systems. Useful system features include high-throughput, automation, robotic arms, automated liquid handling and associated database systems. Accessories in sample management include barcode scanners, heat sealers and tubes.Robotic InstrumentsRobotic instruments can be used for high-throughput automation of many lab processes. Such processes use instruments for assays like cell based assays and ELISA, for sample preparation like shakers, centrifuges and incubators, and for analysis such as sequencing and western blot analyzers. Useful features of robotic instruments include speed, reproducibility, barcode readers, software and automation.Robotic WorkstationsRobotic workstations are automated platforms enabling the user to perform high-throughput, multi-application processes, from sample preparation tasks such as PCR set-up, DNA purification and NGS library preparation, to integrated sample prep and analysis workstations. Automation makes processes consistent, fast, precise and fully walk-away. Find the best robotic workstations in our peer-reviewed product directory: compare products, check customer reviews and receive pricing direct from manufacturers.Automated Liquid HandlingAutomated liquid handling equipment is used to mix, dilute and dispense allotted volumes of liquid into microplates and other vessels automatically. The robotic, liquid handling arms can dispense from single channel to 3456 multichannel as well as operate nanoliter dispensing, enabling high throughput of samples. Find the best automated liquid handlers in our peer-reviewed product directory: compare products, check customer reviews and receive pricing direct from manufacturers.pH and Conductivity MetersIon and pH meters, used for electrochemical techniques and measurements, measure the concentration of specific ions using electrodes (probes) and a meter. Features of ph and ion meters to consider include temperature compensation, auto-calibration, adjustable resolution, measurable range and accuracy. Meters can be handheld, portable, benchtop and modular.Food and Beverage AnalyzersFood and Beverage Analyzers are commonly used to provide information about the chemical composition, structure and physical properties of food materials.Food and Beverage ProcessingFood and Beverage Processing involves the preparation of food products for further analysis. Typical instrumentation includes blanchers, color sorters, cookers, grinders, and refrigeration. These are used to replicate the processes commonly used in the commercial preparation of food and beverages.Particle CharacterizationParticle characterization instruments are used to determine particle size distribution, shape, surface area, zeta potential, density and porosity of particles and materials. Multiple tecchniques are available for determining particle size, shape and count including dynamic light scattering (DLS), laser diffraction, electrozone (Coulter technique), imaging particle analysis and single particle optical sensing. Determine the density of your material with a gas pycnometer or examine its surface area and porosity with gas adsorption analyzers and mercury porosimeters. Find the best particle characterization instruments in our peer-reviewed product directory: compare products, check customer reviews and receive pricing direct from manufacturers.EnzymesEnzymes are macromolecular biological catalysts used across life science, pharmaceutical and clinical research. Various enzymes can be purchased for research applications including ligases, high fidelity polymerases, nuclease, protease, restriction enzymes, tissue dissociation enzymes and enzyme inhibitors. Find the best enzymes in our peer-reviewed product directory: compare products, check customer reviews and receive pricing direct from manufacturers.GlucoseMilkMilk is a dairy product that contains lactose. It is consumed by infant mammals to provide nutrients from the mother. In 2008, the Chinese milk scandal saw the unlawful adulteration of powdered milk with melamine.Lactose