Thin layer Chromatography (TLC)

The principle of the Thin Layer Chromatography is the same as described for paper chromatography (partition). Instead of paper the Thin Layer Chromatography of very finely powdered silica gel, alumina, polyacrylamide gel, starch gel or kieselguhr, bound to a glass or plastic plate. Mixture is spread as a thin layer on glass or plastic plates. The chromatographic separation is comparatively rapid in TLC. In case of adsorption thin layer chromatography, adsorbents such as activated silica gel, alumina, kieselguhr are used.

Source : Biochemistry by Dr. U. Satyanarayana

Paper Chromatography

This technique is commonly used for the separation of amino acids, sugars, sugar derivatives and peptides. In paper chromatography, stationary phase is a paper, usually cellulose acetate and the mobile phase is a solvent in which the solute in the mixture are soluble. In this technique, a few drops of solution containing a mixture of the compounds to be separated is applied at one end of the paper (Whatman No. 1 or No. 3 Filter paper), usually above 2 to 3 cm. The paper is dried and dipped into a solvent mixture consisting of butanol, acetic acid and water in 4:1:5 ratio. The aqueous component of the solvent system binds to the paper and forms a stationary phase. The organic component that migrates on the paper is the mobile phase. The filter paper is hung vertically into the solvent, the migration of the solvent is upwards by capillary action is referred to as ascending chromatography. In descending chromatography, the solvents moves downwards. As the solvents flows, it takes along with it the unknown substances. The rate of migration of the molecules depends on the relative solubilities in the stationary phase and mobile phase. 

Remove the paper after a sufficient migration of the solvent, dried and sprayed with a chemical of colour development. Identifies the specific spots at different sites. Ninhydrin, which forms purple complex with ∝-amino acids, is frequently used as a coloring reagent. The chemical nature of the individual spots can be identified by running known standards with the unknown mixture. 

Partition Chromatography

Partition chromatography utilizes differences in the relative solubility of the solute molecules between mobile and the stationary phase. The two phases may be liquid-liquid or gas-liquid. This methodology is used for gas liquid chromatography (GLC) and for high performance liquid chromatography (HPLC). 
It includes 

a.       Paper Chromatography

b.      Thin Layer Chromatography

c.       Gal-Liquid Chromatography

Chromatography

Chromatography is technique discover by Russian Botanist Mikhail Tswett in 1906.
Chromatography is the laboratory technique use for separation of organic and inorganic compounds from the mixture. Includes proteins, peptides, amino acids, lipids, vitamins, carbohydrates, etc. It consists mobile phase and stationary phase.
Types of Chromatography.

1.       Partition Chromatography

a.       Paper Chromatography

b.      Thin Layer Chromatography

c.       Gal-Liquid Chromatography

2.       Adsorption Column Chromatography

3.       Ion Exchange Chromatography

4.       Gel Filtration Chromatography

5.       Affinity Chromatography

6.       High performance liquid chromatography (HPLC)

Immunoelectrophoresis

This technique involves combination of the principles of electrophoresis and immunological reactions (antibodies). Immunoelectrophoresis is useful for the analysis of complex mixtures of antigens and antibodies.
The complex proteins of biological samples are subjected to electrophoresis. the antibody is then applied in a trough parallel to the electrophoretic separation. the antibodies diffuse and when they come in contact with antigens, precipitation occurs, resulting in the formation of precipitin bands which can be identified.
Source : Biochemistry by Dr. U. Satyanarayana

Isoelectric Focussing

This technique is primarily based on the immobilization of the molecules at isoelectric pH during electrophoresis. Stable pH gradients are set up (Usually in a gel) covering the pH range to include the isoelectric points of the components in a mixture. as the electrophoresis occurs, the molecules migrates to positions corresponding to their isolelctric points, get immobilized and form sharp stationary bonds. the gel blocks can be stained and identified. by isoelectric focussing, serum proteins can be separated to as many as 40 bonds. Isoelectric focussing can be conveniently used for the purification of proteins.
Source : Biochemistry by Dr. U. Satyanarayana