Although chromatography is a common technique in biochemistry laboratories used for purification, identification and quantification of protein mixtures, laser diffraction is traditionally used for pre-column size and polydispersity management. Both these methods are particularly useful adjuncts to gel-based approaches.

Chromatic Methods: There are two chromatic methods frequently used for protein separation вЂ“ high-performance liquid chromatography and thin-layer chromatography.

This technique is a type of zone electrophoresis that is usually performed in a gel and takes advantage of the fact that a moleculeвЂ™s charge changes with the pH of its surroundings.

Isoelectric Focussing: In this method, different molecules are separated by their electric charge differences.

ItвЂ™s a technique thatвЂ™s widely used in biochemistry, forensics, genetics and molecular biology.

SDS-PAGE separates proteins mainly on the basis of molecular weight as opposed to charge or folding. Proteins can be separated according to solubility, size, charge and binding affinity. The most commonly used technique for protein separation is sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). ItвЂ™s an important approach to studying protein function and the effect of a particular protein on development or a physical function by introducing it into an organism. Protein electrophoresis is the process of separating or purifying proteins by placing them in a gel matrix and then observing protein mobility in the presence of an electrical field. There are three major protein analysis techniques: protein separation, western blotting and protein identification. Hence, they have different molecular structures, nutritional attributes and physicochemical properties. Proteins differ from each other according to the type, number and sequence of amino acids that make up the polypeptide backbone. For example, many thousand actin molecules assemble into a microfilament. Very large aggregates can be formed from protein subunits. By physical size, proteins are classified as nanoparticles, between 1 вЂ“ 100nm. Protein structures range in size from tens to several thousand amino acids. Quaternary structure: The structure formed by several protein molecules which function as a single protein complex.Tertiary structure: The overall shape of a single protein molecule the spatial relationship of the secondary structures to one another.Secondary structure: Regularly repeating local structures stabilised by hydrogen bonds.Primary structure: The amino acid sequence.There are four distinct aspects of a proteinвЂ™s structure: While most proteins can fold unassisted through the chemical properties of their amino acids, others require the aid of molecular chaperones. The shape that a protein folds into naturally is known as its native conformation. Most proteins fold into unique three-dimensional structures.

This understanding is the topic of the scientific field of structural biology, which employs traditional techniques such as X-ray crystallography, NMR spectroscopy, and Circular Dichroism spectrometry to determine the structure of proteins. To be able to perform their biological function, proteins fold into one or more specific spatial conformations driven by a number of non-covalent interactions such as hydrogen bonding, ionic interactions, Van der Waals forces, and hydrophobic packing. The size of a protein is an important physical characteristic and scientists often use particle size analysers in their studies to discuss protein size or molecular weight. Many proteins are enzymes that catalyse biochemical reactions and are vital to metabolism. Essential parts of organisms, they participate in virtually every process within cells. Proteins do most of the work in cells and are required for the structure, function, and regulation of the bodyвЂ™s tissues and organs. There are 20 different types of amino acids that can be combined to make a protein and the sequence of amino acids determines each proteinвЂ™s unique 3-dimensional structure and its specific function. Proteins are made up of hundreds of thousands of smaller units that are arranged in a linear chain and folded into a globular form. TheyвЂ™re large, complex molecules that play many critical roles in the body. Proteins, also known as polypeptides, are organic compounds made up of amino acids.

Protein sequence analysis