Electrophoresis is defined as a technique, where the migration and separation of charged particles (ions) occur under the influence of an electric field. The process does not affect the molecular structure of compounds being separated, yet it is highly sensitive to differences in molecular charge and mass of the components of the sample (Figure 1). … Read More

Thin-Layer Chromatography (TLC)

Thin Layer Chromatography (TLC) is a simple and inexpensive technique used to judge the purity of a synthesized compound or to indicate the extent of progress of a chemical reaction. It is a solid-liquid form of chromatography where the stationary phase is normally a polar absorbent and the mobile phase is a single solvent or … Read More

Paper Chromatography

Paper chromatography is an analytical technique used for separation of mixtures into their components for identification (Figure 1), purification, and quantification. It is a useful technique as it is quick, has high resolution and ease of detection when separating small samples. The mobile phase is usually an alcohol solvent mixture, while the stationary phase is … Read More

Applications of Radioactive Isotopes

Applications of radioactive isotopes are varied in several areas of science. It ranges from the field of agriculture to the diagnosis of diseases. Agricultural Applications Radioisotopes are being widely used in plant nutrition studies and several researches are being conducted in many countries for using radiation sources to preserve certain types of agricultural produce, such … Read More


In chemical science, dialysis refers to the process of separation of suspended colloidal particles from dissolved ions or molecules of small dimensions (Figure 1). Separation occurs due to their unequal rates of diffusion through the pores of a semipermeable membrane, such as dialysis tubing. The process of dialysis was first observed in 1861 by a … Read More


Crystallization is a solid-liquid separation technique, in which mass transfer of solute from liquid solution (parent phase) to a pure solid crystalline phase occurs (Figure 1). It is used to purify solid compounds. Cystallization is the oldest method for recovering solids from a solution. Fractional crystallization is a step-wise separation technique, which relies upon liquid-solid … Read More

Fractional distillation

Fractional distillation is a process to separate mixtures of volatile liquids and miscible liquids. It is commonly used to separate various components (difference in boiling point is less than 25oC) of a mixture depending upon their boiling points. Principle Involved If a liquid is heated in closed container, some molecules present at the surface of … Read More

Freeze Drying

Freeze Drying is also known as Lyophilization or cryo-dessication. It is a process for removing water from the substance by the process of dehydration under vacuum while substance is in frozen state. Lyophilization technology is used to freeze-dry products, such as biologicals, bacterial cultures, analytical chemistry moieties, and therapeutic molecules (e.g., antibodies, vaccines, drugs, and … Read More


Radioactivity is a spontaneous process by which unstable atoms of an element lose excess energy by emitting that energy in the form of particles or electromagnetic waves to gain stability. This course introduces concepts of radioactivity, and covers the following topics: measurement of radioactivity radioactive waste disposal. Isotopes of an element differ in their physical … Read More


Radiopharmaceuticals (RP) are chemical substances that contain radioactive atoms within their structure. They are used as tracers in nuclear medicine technology for diagnostic and therapeutic purposes. This course covers various kinds of radiopharmaceuticals, calculating effective half life, determining radiochemical purity, and applications of radiopharmaceuticals used in medical science. Characteristics More than 95% of radiopharmaceuticals are … Read More