Biotechnology π Flashcards
Molecular biology lab procedure that is used to synthesize many copies of a desired fragment of DNA
Steps (repeated multiple times)
- DNA is denatured to generate 2 separate
- During cooling, excess premade DNA primers anneal to a specific sequence on each strand to be amplified
- Half-stable DNA polymerase replicates the DNA sequence following each primer
Polymerase chain reaction
Used to deduce original sequence of DNA
Dideoxynucleotides halt DNA polymerization at each base, generating sequences of various lengths that encompass the entire sequence
Sanger DNA sequencing
A DNA sample is electrophoresed on a gel and then transferred to a filter
The filter is then soaked in a denaturant and subsequently exposed to a labelled DNA prove that recognizes and anneals to the complementary strand
The resulting double stranded labeled piece of DNA is visualized when the filter is exposed to film
Used to determine which restriction fragments of DNA are associated with a particular gene
Southern blot (DNA sample)
Similar technique, except that Northern blotting involves radioactive DNA prove binding to sample RNA
Used to measure sizes and amounts of specific mRNA molecules to answer questions about gene expression
Northern blot (RNA sample)
Sample protein is separated via gel electrophoresis and transferred to a filter
Labelled antibody is used to bind to relevant protein
Used to measure amount of antigen (proteins) or antibody
Western blot (Protein sample)
Thousands of Nucleic acid sequences are arranged in grids on glass or silicon
DNA or RNA probes are hybridized to the chip, and a scanner detects the relative amounts of complementary binding
Microarrays (color coded)
Enzyme-linked immunosorbent assay
A rapid immunologic technique testing for antigen-antibody reactivity
Patientβs blood is probed with either:
- test antigen (coupled to color-generating enzyme) to see if immune system recognizes it
- test antibody (coupled to color-generating enzyme) to see if a certain antigen is present
Intense color reaction: (+) result
ELISA
Fluorescent probe binds to specific gene site of interest
Specific localization of genes and direct visualization of anomalies (e.g. microdeletions) at molecular level
FISH (Fluorescence in situ hybridization)
Inherited difference in the pattern of restriction
Important in understanding various single-gene and multigenic diseases
Useful as a diagnostic tool for diseases involving single-base changes, or deletions/insertions of DNA into a restriction fragment
Restriction Fragment Length Polymorphism
Is the production of recombinant DNA molecules that is self-perpetuating
Tissue mRNA is isolated and exposed to reverse transcriptase, forming a cDNA (lacks introns) library
Cloning
Steps of cloning methods
DNA fragments are inserted into bacterial plasmids that contain antibiotic resistance genes. These plasmids can be selected for using media containing antibiotic and amplified
Restriction enzymes cleave DNA at 4-6 base pairs palindromic sequences, allowing for insertion of a fragment into a plasmid
Treatment option for diseases caused by deficiency of a gene product
The strategy is to clone a gene into a vector that will readily be taken up and incorporated into the genome of a host cell
Gene therapy