advanced higher Biology key area 1.1 ( labratory techniques for biologists)

Affinity

The degree to which a substance is attracted and tends to bind to another

Affinity chromatography

A technique used to separate and purify proteins based on a specific binding interaction between an immobilised ligand and its binding parter

Antigen

A specific protein with which antibodies can bind in an immune response

Aseptic technique

Procedures in place to prevent contamination ( including, sterilising work surfaces and work surfaces)

Bright-field microscopy

Commonly used to observe whole organisms, parts of organisms parts of an organism

Buffer

A solution used to control the PH and keep it constant

Centifugation

A process that used centrifugal forces to separate components of different density’s in a mixture

Chromatography

A technique used to separate different substances

Coloromiter

A device used to measure the absorbance of a specific wavelength of light by a solution

Culture media

A nutrient rich growth medium providing basic requirements for cell growth ( amino acids, glucose, salts, water)

Fluorescence

The emission of light of a different wavelength to that which is absorbed

Fluorescence microscopy

A technique that uses specific fluorescent labels to bind to an visualise certain molecules or structures

Gel electrophoresis

Technique used to separate samples of nucleic acid and protein by size, introduced to a gel and moved through and electrical current, smaller fragments move further than larger ones

Growth factors

Proteins that promote cell growth and proliferation

Haemocytometer

Microscope grid used to estimate the total number of cells within a sample

Hazard

Anything that poses a potential risk or threat to an individual or the environment

Immunoassay

Technique used to detect and identify specific proteins; antibodies linked with reporter enzymes ( i,e cause a colour change)

Inoculum

Starting material used to grow a culture from

Isoelectric point ( IEP)

The PH at which a soluble protein has no net charge and will precipitate out of solution

Linear dilution series

A series of dilutions that differ by a constant proportion

Monoclonal antibodies

Stocks of identical antibodies that are specific to a particular antigen

Native gel electrophoresis

Does not contain SDS and does not denature the molecule, so proteins are separated by their size, shape and charge

Pathogenic

Causing disease

Primary cell lines

A culture of cells isolated directly from animal or plant tissues; they have a finite lifespan and limited extension capacity

Reporter enzyme

An enzymes linked to an antibody specific to a protein antigen; they are used in Immunoassay techniques

SDS-PAGE

Electrophoresis in which the gel contains SDS, which gives all the mollecules an equally negative charge and denatures them, separating proteins by size alone

Serum

Vitally important as a source of growth factors, hormones, minerals and lipids

Standard curve

A graph that can be used to determine the concentration of an unknown solution

Supernatant

The liquid that lies above a solid residue ( or pellet) in centrifugation

Turbidity

A measure of the degree to which a fluid looses transparency due to suspended particles

Vital staining

A technique in which a harmless dye is used to stain either living tissue cells or dead cells for micropscipal observations, allows for a vital cell count

Western blotting

An analytical technique used to identify and locate specific proteins in a sample of tissue homognate or extract based on their ability to bind to specific antibodies