Unit 1.1 Lab techniques Flashcards
serial dilution
A serial dilution is the repeated dilution from a stock solution to reduce conc of a substance. used a lot in microbiology
colorimeter
measures absorbance and transmission of specific wavelengths of light by a solution
absorbance (COLORIMETER)
how much light has been absorbed by the sample
transmission (COLORIMETER)
how much light passed through the sample without being absorbed
Ways of finding unknown concentration of solution
Standard curve, Titration
centrifugation
spins a sample at high speed and separates it according to size and density
Two separated parts after centrifugation called
pellet (largest and densest part) and supernatant (liquid)
gel electrophoresis
separates based in charge or size. uses current flowing through a buffer to separate proteins. Gel acts as a sieve
process. type of gel electrophoresis
SDS page
SDS page
proteins denatured and given negative charge so can be separated based on charge as migrate towards positive electrode. small travels further
iso electric point charge
neutral charge and forms a precipitate
ph below iso electric point charge
positive
ph above iso electric point charge
negative
process using isoelectric point
isoelectric focussing
paper chromatography
dot at bottom of paper and placed in solution, moves up depending on properties
thin layer chromatography
use an absorbent material like silica gel and substance will move up depending on properties
affinity chromatography
immobilised ligand column, substance goes through and target protein binds to ligand, rest washed away
chromatography
separates mixtures of proteins and amino acids
mixture is dissolved in liquid in what phase (chromatography)
mobile phase
separated in what phase (chromatography)
stationary phase
immunoassay
using antibodies to detect prescience and concentration of protein
immunoassay is used in what ways medically
detection of HIV, food allergens, and certain drugs
antibodies used must use a detectable label eg
reporter enzyme
process (types of immunoassay)
ELISA enzyme linked immunosorbent assay, western blotting, immunohistochemistry
types of ELISA
direct indirect sandwich
western blotting and immunohistochemistry
allows proteins to be extracted from a tissue
monoclonal antibodies
antibodies created in a lab by exposing animal to antigen and fusing B lymphocytes with myeloma cells and then cultured in HAT
Types of microscopy
bright field, fluorescent
fluorescence microscopy
absorbs specific wavelength and emits different longer one. emits different colour
Haemocytometer calculation order
Count NE, times 2, times 10, times 1000
flow cytometry
cells pass through light beam, interrupting it so it can identify it and characteristics
Cell culture requires
environmental factors to be controlled, water, salts, amino acids, vitamins, glucose, (animal requires growth factors eg foetal bovine serum)
inoculum
cells used to inoculate culture media, contains cells that are released from source tissue using proteolytic enzymes
explants
small pieces of tissue
aseptic technique
sterile work area, sterile handling, good personal hygiene, sterile media and reagents
viable cell count
live cells/ total cells= % viability
