World of Biochemistry

Immunoelectrophoresis was first coined by Grabar and Williams in 1953.  * Principle :- Immunoelectrophoresis created a important development in protein identification and in immunology. After electrophoretic separation of serum proteins in an agar gel, the serum proteins were allowed to diffuse against antibodies, leading to a pattern of precipitation arcs in the agar representing the major constituents among the serum proteins. immunoelectrophoresis is also known as electro-immunodiffusion; it is a simple and rapid method to quantify the amount of either a protein or a protein mixture.  Immunoelectrophoresis refers to precipitation in agar under an electric field. It is a process of a combination of immuno-diffusion and electrophoresis. An antigen mixture is first separated into its component parts by electrophoresis and then tested by double immuno-diffusion. * Protocol :- Agarose gel is prepared on a glass slide put in a horizontal position.         ...

* Principle :- The blue–white screen is a screening technique that allows for the rapid and convenient detection of recombinant bacteria in vector-based molecular cloning experiments. DNA of interest is ligated into a vector. The vector is then inserted into a competent host cell viable for transformation, which are then grown in the presence of X-gal. Cells transformed with vectors containing recombinant DNA will produce white colonies; cells transformed with non-recombinant plasmids (i.e. only the vector) grow into blue colonies. This method of screening is usually performed using a suitable bacterial strains The blue-white screen is a screening technique that allows for the detection of successful ligations in vector-based gene cloning. DNA of interest is ligated into a vector. The vector is then transformed into competent bacterial cells Blue-White selection is the technique used to determine whether the host (Bacteria) which is transformed has the plasmid (vector) with the gene of...

Two bacteriologists, Herbert Edward Durham (-1945) and Max von Gruber (1853–1927 ), discovered specific agglutination in 1896 * Principle :- The reaction  between a particulate antigen and an antibody results in visible clumping called agglutination.   Since then, tests to detect microbial and viral infections, autoimmune diseases, hormones, drugs and serum proteins have been developed and marketed by many companies worldwide. Letex agglutination tests have been applied in clinical laboratories for the detection and diagnosing many infections such as Hepatitis B, H.influenzae, N. meningitidis, etc.. In rheumatoid arthritis (RA), IgG antibodies produced by lymphocytes in the synovial joint react with the IgM antibodies (RF, rheumatoid factor) to generate immune complexes that activate the complement and cause the tissue destruction. The RA is of diagnostic significance. *Types of agglutination 1)Slide agglutination: Serotyping 2)Tube agglutination: e.g. Widal test....

The tetracyclines were discovered by Benjamin Minge Duggar in 1945 as natural products,  * Principle :----- The tetracycline ,a large family of antibiotics Tetracyclines retain an important role in medicine, although their usefulness has been reduced with the onset of antibiotic resistance. Tetracyclines remain the treatment of choice for some specific indications.    Tetracyclines are growth inhibitors (bacteriostatic) rather than killers of the infectious agent (bacteriocidal) and are only effective against multiplying microorganisms. They inhibit protein synthesis by binding reversibly to the bacterial 30S ribosomal subunit  *Chemical Formula-:            C22H24N2O8 * Classified according to source -: 1)Naturally occurring Tetracycline- •Chlortetracycline •Oxytetracycline •Demeclocycline 2)Semi-synthetic- •Lymecycline •Meclocycline (no longer marketed) •Methacycline •Minocycline •Rolitetracycline •Doxycycline •Glycecyclines •Tigecycli...

* Principle :- In recent years, the determination of vitamin C has become an important subject in the field of biochemistry and commercial foods. This is because vitamin C plays an important role in maintaining human health. Ascorbic acid (vitamin C) is a water-soluble vitamin which can be found in many biological systems and foodstuffs (fresh vegetables and fruits, namely, citrus).  Ascorbic acid plays  an important role in collagen biosynthesis, iron absorption, and immune response activation and is involved  in wound healing and osteogenesis. It also acts as a powerful antioxidant which  fights against free-radical induced diseases . Nevertheless,  an ascorbic acid excess can lead to gastric irritation, and the metabolic  product of vitamin C (oxalic acid) can cause renal problems .  Ascorbic acid is a labile substance, as it is easily  degraded by enzymes and atmospheric oxygen. Fruit, vegetables and their products are important sources of asc...

* Principle :-  Saponification value is defined as the number of milligrams of KOH required to completely hydrolyse (saponify) one gram of the oil. The acid value is determined by directly titrating the oil in an alcoholic medium against standard potassium hydroxide solution. Acid value refers to the amount of "free" fatty acids in the oil. Saponification value refers to the amount of esters that can be hydrolysed and turned into soap. Both these values are given as mg KOH per g of oil . In practice a known amount of the oil  is refluxed with excess amount of standard alcoholic potash solution and the unused alkali is titrated against a standard acid. The neutralization reaction between the fatty acids in oils and bicarbonate in an ethanol (80%) aqueous solution was performed in a closed headspace sample vial, from which the carbon dioxide generated from the reaction was detected by HS-GC. It was found that the addition of ethanol can effectively improve the reaction of fatty...