UV-Vis spectroscopy (Ultraviolet-visible spectroscopy) is an analytical technique used to measure the amount of ultraviolet and visible light absorbed or transmitted by a chemical sample. It measures light in UV and visible region. The reading is taken as absorbance or transmittance. This technique relies on interaction between electromagnetic radiation and matter. When molecules are exposed … Read more
UV-Visible (UV-Vis) spectroscopy is an analytical technique used to measure the absorption or transmission of ultraviolet and visible light by a sample. It works in UV region (about 190–400 nm) and visible region (about 400–800 nm). It is a fast and simple method used in both qualitative and quantitative analysis. The absorption is recorded as … Read more
Objective lens is the most important lens of an optical microscope, which is kept closest to the specimen. It is the first lens that collects the light coming from the specimen (emitted or reflected). It bends the light rays and forms a real, magnified image at an intermediate image plane. This primary image is then … Read more
Microscope condenser is an optical lens system placed below the stage of the microscope between the light source and the specimen. It is used to collect the divergent light rays and concentrate them as a cone of light on the specimen. It helps in giving uniform illumination so that the light can pass through the … Read more
Ion Exchange Chromatography (IEC) is a chromatographic separation technique used to separate and purify molecules based on their net surface charge. It works mainly for charged biomolecules like proteins, peptides, amino acids and nucleic acids. In this method, separation depends on electrostatic attraction between the sample and the charged stationary phase. Ion exchange chromatography is … Read more
Ever wondered about the little scientific marvels you hold in your hand during chemistry or biology labs? We’re shining a spotlight on one such unsung hero of the scientific world – disposable glass pasteur pipettes. These handy tools, so often taken for granted, have a fascinating history and a crucial role in your experimental success. Let’s dive in and … Read more
Glass dropper pipette is a small glass device used to transfer liquid in drop by drop form. It is also called as eye dropper or Pasteur pipette. It is mainly used when a small quantity of liquid is to be taken and dispensed in controlled drops. It is generally made of three parts. A rubber … Read more
ONPG test is a rapid biochemical test used in microbiology to detect the presence of β-galactosidase enzyme in bacteria. It is used to identify organisms which can produce β-galactosidase but may not ferment lactose in routine lactose tests. Normally lactose fermentation needs two enzymes. One is lactose permease which transports lactose inside the cell. Another … Read more
The ability to develop in the presence of varying concentrations of sodium chloride (NaCl) has been used to distinguish between various bacteria.
Sulfur Reduction Test (H2S production test) is a biochemical test used to see the ability of bacteria to reduce sulfur containing compounds and liberate hydrogen sulfide gas (H2S). It is used mainly for differentiation of Gram negative enteric bacilli. It helps to separate H2S producers like Salmonella and Proteus from non producers like Shigella and … Read more
