Chapter 17 Flashcards
(58 cards)
What is biotechnology?
use of biological agents to make technological advances
Applied biotechnology
- medicine
vaccine development, drug discovery - agriculture
GMOs and crop yields - energy
biofuels, environmental remediation
isolation and extraction of DNA from cells procedure
- break cell wall
lysis buffer with SDS - Degrade macros
proteases and ribonucleases - remove and charge proteins
“salting out” with NaCl - precipitate and remove contaminants
wash with ethanol - rinse and remove target DNA
elution buffer with tris-EDTA - storage at -80 C
Gel Electrophoresis
Separation and visualization technique
gel creates “pores”
molecules separate based on size
gel between two electrodes and submerged in buffer
Gel used for electrophoresis in proteins
acrylamide gel (verticle)
Gel used for electrophoresis in DNA
agarose gel (horizontal)
How do solutions separate in gel electrophoresis
mass/charge ratio
fragments have negative charge so move toward positive end
smaller fragments move farther
negative electrode gel electrophoresis
Cathode
positive electrode gel electrophoresis
Anode
Dyes used in electrophoresis
“walk up DNA stairs”
ethidium bromide
super green (less toxic)
Southern blotting techniques
DNA
Northern blotting techniques
RNA
Western blotting techniques
Protein
Polymerase Chain Reaction
used for rapid DNA replication
billions of copies within hours
now fully automated
Polymerase Chain Reaction steps
- Denaturation
high heat 95 C
double -> single strands - Annealing
50 to 60 C
primer binds to strands - Extension
72 C
Taq DNA polymerase
adds complementary bases - each cycle doubles DNA
How many cycles are needed in PCR
20-30
Problems with PCR
No proofreading
mistakes in copying possible
DNA cloning
isolation of DNA carrying a gene, amplify DNA, produce multiple copies of one gene
Why is identifying genes on chromosomes diffficult
100s of genes/chromosome
each gene may be 1/100,000 of DNA long
Bacterial Plasmids
Accessory “circular” DNA not needed for normal function is easily inverted to sequence of interest
cloning vectors carry DNA into host cell and are incorporated into genome
instances of reproductive cloning
mammals specifically
1997: Dolly the sheep
cloned successfully from adult cells which resulted in early arthritis, euthanized at age 6
2018: primates (not USA)
Therapeutic cloning
nose/ear grown
pig heart transplant
produce various cell types/provide cells/tissue for treatment.
Practical applications: disease/diagnostic treatment
PCR to confirm pathogens (COVID 19)
higher specificity than protein assay
less likely to receive false negative
Practical applications: Personalized genomic analyses
personalized medicine
genetic profile generated
predict treatment effectiveness
decide on treatment regime
especially for breast cancer (120 types)