Patricia Linton Manchester Metropolitan University
It’s just so amazing – that’s what!
It’s not science fiction – it’s science fact!
DNA - Encodes all of the genetic information needed for the development and functioning of all cells.
Discipline is full of amazing facts
TRANSCRIPTION RNA PROCESSING DNA RNA transcript 3 5 RNA polymerase Poly-A Poly-A RNA transcript (pre-mRNA) Intron Exon NUCLEUS Aminoacyl-tRNA synthetase AMINO ACID ACTIVATION Amino acid tRNA CYTOPLASM Poly-A Growing polypeptide 3 Activated amino acid mRNA TRANSLATION Cap Ribosomal subunits Cap 5 E P A A Anticodon Ribosome Codon E The central dogma DNA RNA PROTEIN
Uses of molecular biology – endless – revolutionised science
Production of recombinant proteins for treatment of disease
Determining the genetic basis of cancer – thereby improving treatment and prognosis
Diagnosis of disease – fast diagnosis of HIV/TB – infectious diseases
pest resistance/ drought resistance/increased productivity
Manufacture of proteins, strain improvement
Used to place criminals at scene of crime or rule out suspects – important for conviction
Analysis of ancient DNA in ceramic food vessels
Identification of species
Clean-up of oil spills
(a) Tobacco plant expressing a firefly gene (b) Pig expressing a jellyfish gene
Kary Mullis – Genius or eccentric? ‘ Science grows like a weed every year’ ‘ Each of us have things and thoughts and descriptions of an amazing universe in our possession that kings in the 17th Century would have gone to war to possess’ ‘ Science consistently produces a new crop of miraculous truths and dazzling devices every year’ ‘ I have had an encounter with an extraterrestrial in the form of a fluorescent raccoon’ ??????? You can read his Nobel lecture here: http://nobelprize.org/nobel_prizes/chemistry/laureates/1993/mullis-lecture.html
PCR – in the dark ages 8 BORING hours per PCR! 95º C 5 min 35 times 55º C 3 min 72º C 5 min
Individual rows of receptacles can be heated – can try lots of reaction temperatures in one ‘run’
The different steps of PCR
Mg 2+ ions
The temperature profile of a PCR cycle is controlled by the thermal cycler program which results in a near exponential increase in PCR product accumulation for about the first 30 cycles. The 3 Os!!!!!
• Used to separate molecules based on their charge and size
• Agarose or acrylamide gels can be used to separate DNA fragments
• DNA is acidic; it migrates from the negative to the positive
end of the gel
each fragment’s migration rate is inversely proportional to
the log of its molecular
Mixture of DNA mol- ecules of different sizes Power source Longer molecules Shorter molecules Gel Anode Cathode 1 2 Power source – + + –
Steps in DNA fingerprinting:
DNA isolated from tissue sample or PCR’d up
DNA cut into fragments with enzymes
DNA with different sequences produce fragments of different sizes
Can use restriction enzymes to cut either side of VNTRs for genetic typing
Fragments separated on basis of size and visualized
Each person’s set of fragments is unique
DNA Fingerprinting – identification of the remains of the Russian Royal Family
DNA fingerprinting showed that 9 different people were buried in the Ekaterinburg grave.
Romanovs would be more similar in pattern to each other than to non-relatives.
All of a child’s bands must be present in one or both of the parents.