laboratory techniques for biologists.

What’s the difference between linear and log dilution?

In linear concentrations are separated by an equal interval like 0,0.2,0.4,0.6,0.8. A log dilution is where concentrations are separated by a constant proportion for example from 10-1,10-2,10-3,10-4,10-5

What is the formula used for dilution calculations?

V1C1=V2C2 V=volume of starting solution needed to make new solution C1=concentration of starting solution V2=final volume of new solution C2=final concentration of new solution.

What is the definition of a buffer solution?

Its a solution which resists changes in pH when small quantities of an acid or an alkali are added to it they are used as a means of keeping pH at a nearly constant value.

what does a standard curve represent?

the relationship between two quantities.

what is used to measure turbidity?

Colorimeter

what is chromatography?

A set of techniques which separates components of a mixture.

how does paper and thin layer chromatography work?

The solvent moves up through the chromatogram and carries the components with it, they travel at different rates depending on their solubility.

How does affinity chromatography work.

Relies on the binding interactions between a protein and another substance (a ligand) it can be used to purify a protein.

how does Gel electrophoresis work?

Gels are separated by their size, shape and charge.

How does the iso-electric point work?

the IEP of a protein is the pH at which a soluble protein has no net charge and will form a solid and precipitate out of the solution.

Tell me about Antibodies.

They are Y shaped proteins made by white blood cells and they bind very specifically to antigens.

why are antibodies useful to detect the diagnosis and detection of a disease?

They are very specific and can be used to indicate the presence of particular proteins, stock of monoclonal antibodies are used in immunoassays as they all have the same specificity (they all bind to the same antigen)

explain the process of centrifugation?

Substances are separated due to their density