Lab technique Flashcards
Colorimeter
To quantify concentration and turbidity
Blank
Deionised water
Centrifugation
Separates substances according to differing density
Pellet
The more dense components
Supernatant
The less dense liquid fraction
Paper and Thin Layer chromatography
Separates substances such as amino acids and sugars according to solubility
Affinity chromatography
Separates a specific soluble protein
Gel electrophoresis
Separates proteins or nucleic acids using current flowing through a buffer. The proteins are separated based on shape, size and charge.
Native
Folded state
Non-native
Unfolded state ( due to heating the molecules in the presence of a detergent )
All molecules have an equally negative charge and denatures them.
SDS page
Separates proteins by size alone
Isoelectric point
The pH at which a soluble protein has not net charge. Proteins are insoluble at their isoelectric point and so will form a precipitate.
Immunoassay techniques
Used to detect and identify specific proteins
Monoclonal antibodies
Derived from a single cell line.
Stocks of antibodies with the same specificity.
In ELIZA, why are the test wells washed between stages ?
To prevent a false positive result from being obtained.
Bright Field Microscopy
Used to observe :
Whole organisms
Parts of organisms
Thin sections of dissected tissue
Individual cells
Fluorescence microscopy
Uses specific fluorescent labels to bind to and visualise certain molecules / structures within cells or tissues.
Aseptic technique
Eliminates unwanted microbial contaminants when culturing micro-organisms or cells.
Broth
Contains suitable nutrients for growth of cells
Medium
Contains growth factors from serum
Primary cell lines
Divide a limited number of times
Haemocytometer
Method used to count cell density
Vital stain
Distinguishes living from dead cells
Vital stains only stain dead cells
Disadvantages of unsung a haemocytometer
Time consuming
Clumping of cells
Small cells are difficult to locate
Dead cells not distinguished from live unless stained
