What is TLC Bioautography?
Background: TLC bioautography is a hyphenated technique combining planar chromatographic separation and in situ biological activity detection. This coupled method has been receiving much attention in screening bio-active natural products because of its properties of being simple, rapid, inexpensive, and effective.
How do you do TLC Bioautography?
In contact bioautography, antimicrobial agents diffuse from a developed TLC plate or paper to an inoculated agar plate , , . The chromatogram is placed face down onto the inoculated agar layer for a specific period to enable diffusion. Then the chromatogram is removed and the agar layer is incubated.
What is TLC protocol?
Thin-layer chromatography, or TLC, is a technique used to separate organic compounds based on differences in their polarities. The bottom of the plate is then immersed in the development solvent, which is usually an organic solvent that is less polar than the stationary phase.
What can TLC chromatography be used for?
Thin Layer Chromatography. Thin-layer chromatography (TLC) is a very commonly used technique in synthetic chemistry for identifying compounds, determining their purity and following the progress of a reaction. It also permits the optimization of the solvent system for a given separation problem.
How does chromatography work?
Chromatography is a method of separating mixtures by using a moving solvent on filter paper. The solvent flows along the paper through the spots and on, carrying the substances from the spot. Each of these will, if the solvent mixture has been well chosen, move at a different rate from the others.
How do you increase retention factor?
In liquid chromatography, the easiest way to increase a solute’s retention factor is to use a mobile phase that is a weaker solvent. When the mobile phase has a lower solvent strength, solutes spend proportionally more time in the stationary phase and take longer to elute.
What effects retention factor?
Retention Factor Rf values and reproducibility can be affected by a number of different factors such as layer thickness, moisture on the TLC plate, vessel saturation, temperature, depth of mobile phase, nature of the TLC plate, sample size, and solvent parameters. These effects normally cause an increase in Rf values.
What do Rf values tell us?
What does the Rf value tell you? A pigment’s Rf value is determined by how high it moves on the paper, which indicates how soluble it is in the solvent. A smaller Rf value generally indicates a larger scale, less soluble pigment while a near-one Rf value indicates a highly soluble pigment.
What can be performed on TLC bioautography?
The antimicrobial, antioxidant and enzyme inhibitory activities can be performed on TLC bioautography. This method is mainly used for preliminary screening natural products possessin …
What is direct bioautography hyphenated directly with thin-layer chromatography?
In so-called direct bioautography, i.e. bioautography hyphenated directly with thin-layer chromatography (TLC-DB), both separation and microbial detection are performed on the same TLC plate. Generally, the method measures antibacterial properties of analyzed substances, i.e. changes in bacterial growth.
What is bioautography and how does it work?
Bioautography is a microbial detection method hyphenated with planar chromatography techniques. It is based mainly on antimicrobial or antifungal properties of analyzed substances. The review discusses three versions of bioautography, i.e. contact, immersion and direct bioautography. The more concern is given to the last one.
What is TLC bioassay used for?
Earlier TLC bioassay methods were developed to detect the inhibition of enzymes in various diseases; viz. Alzheimer’s disease involved the acetyl cholinesterase ( 21) and α- and β-glucosidase having therapeutic importance in Type 2 diabetes and antiviral infections ( 22, 23 ).