Electrophoresis is a common lab procedure for identifying and separating macromolecules. It was first observed in the early 1800s by a university scientist in Moscow. Like many discoveries, it was accidental, but has proven itself useful for many research scenarios. By applying electricity, technicians use the particles’ negative or positive charges to make them migrate through porous matrix, such as an agarose gel. When positively charged molecules are present in a sample, they will creep towards the negative current (cathode), while negatively charged molecules will migrate to the positive current (anode).
Besides a source of electricity and gel, this kinetic test requires buffer to help prevent temperature and pH extremes. The type of gel used depends on the sample and application. Gels are “solid,” but porous. Within the gel, larger molecules will travel more slowly and smaller molecules will move quickly. Therefore, molecular size is another w
Gel electrophoresis allows for the separation of nucleic acids (DNA or RNA) and proteins based on their size. Electrophoresis is used by labs studying vaccines, medications, forensics, DNA profiling or other life science applications. The technique is also used in industry such as mining or food sciences.
Gel electrophoresis utilizes a porous gel matrix through which proteins or nucleic acids migrate. Both nucleic acids and proteins possess a net-negative electrical charge, a property that is leveraged to facilitate the migration of the desired molecule through the medium.
The gel box features a cathode at one end and an anode at the other. The box is filled with an ionic buffer, which creates an electric field when a charge is applied. Since the proteins and nucleic acids have a uniformly negative charge, the molecules will migrate towards the positive electrode. The speed of this migration is dependent on how easily the molecules move through the pores of
The field of calorimetry is used to determine the heat resulting from chemical reactions and physical state changes, in addition to the heat capacity of non-combustible materials. Calorimetry has been studied for over 200 years and has proved useful in multiple scientific disciplines. From thermodynamics to modern combustion engines to food sciences, the utility of calorimetry in determining the enthalpy (heat transfer at a constant pressure) of a reaction cannot be overstated. Keep reading to discover two of the most common instruments used for calorimetric measurements, along with examples of their applications.
Several options exist for determining the composition, concentration, and purity of a laboratory sample. Among the most commonly used techniques are Ultraviolet/Visible (UV/Vis), Infrared (IR), and Atomic Absorption Spectrometry. Each technique is capable of providing some or all of these pieces of information you need. In addition, each of these instruments is capable of interrogated different types of samples, including air, industrial chemicals, biological fluids and foods. Therefore, selection of an appropriate technique for analysis of your sample is essential in obtaining the desired data.
Several types of UV/Vis spectrophotometers exist, however they all operate on the same basic principle. In short, discrete bandwidths of light are passed through a sample. “Visible” light energy can be seen by humans, while its close neighbor, ultraviolet, cannot. In the entire electromagnetic spectrum ranging from hi
USP Compliance of Pharmaceutical Labs
Absorption spectroscopy is an important analytical chemistry technique used in pharmaceutical analysis. The United States Pharmacopeia (USP) defines absorption spectroscopy as “the measurement of an interaction between electromagnetic radiation and the chemicals, or atoms, of a chemical substance.” To ensure the safety, quality and efficacy of compounds being produced, USP has developed standards and guidelines that must be observed by the pharmaceutical industry.
To meet these guidelines, labs must rigorously follow USP Reference Standards when performing absorption spectroscopy. From a quality control standpoint, absorption spectroscopy assists with compliance in detecting chemical elements within a sample. Instruments with data-transfer capabilities provide traceable reporting, compliant with Good Manufacturing Practices (GMP). There are two popular absorption spectroscopy techniques used in pharma