DNA amp Biotechnology Biotechnology Recombinant DNA Gene splicing Restriction enzymes Sticky ends L igase amp DNA ase DNA sequencing Gene probes DNA profiling Short tandem repeats ID: 516037
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DNA & BiotechnologySlide2
DNA & Biotechnology
Biotechnology
Recombinant DNA
Gene splicingRestriction enzymesSticky endsLigase & DNA-aseDNA sequencingGene probes
DNA profilingShort tandem repeatsGel electrophoresisCapillary electrophoresis
Keywords
KeywordsSlide3
What is biotechnology?
Biotechnology is using living things to create products or to do tasks for human beings.
It is the practice of using plants, animals and micro-organisms and their biological processes to some benefit
eg. in medicine, agriculture and industryResearchers use DNA, genes, yeast, bacteria and cellsSlide4
Why use biotechnology?
For ourselves
Biotechnological research has been used to assist human health in many areas:
antibioticsvaccinesgenetic disordersDNA profiling & forensics
For the environmentBiotechnology is a tool used:to help control pestsfor conservation of plant & animal speciesleach metals from the soil for cleaner miningclean up heavy metal contaminationSlide5
Recombinant DNA & gene splicingSlide6
Recombinant DNA & gene splicing
Recombinant DNA is a method of cutting and pasting a foreign piece of DNA into the DNA of a cell.
It brings
together genetic material from multiple sources, creating new sequences of DNA.Enables the genome to be manipulated very precisely Slide7
Recombinant DNA
Recombinant
DNA is used for
the production of specific proteinsThe first chemical produced by this mehtod was human insulin The human gene is placed into a bacterium which can then use the genetic information to produce the human hormone.
The hormone is refined from the culture of bacteria.Slide8
Recombinant DNA & gene splicing
Steps to gene splicing:
Restriction
enzymesCut the DNA at a specific locationLeaves the DNA strand with ‘sticky ends’
Sticky endsUnattached (unpaired) nucleotidesMatch up with the DNA to be insertedLigation
Ligase enzymes help form the hydrogen bonds between nucleotides
DNA-
ase
helps form the bonds between the side strands (backbone)
Fluorescent green protein transgenic mouseSlide9
Recombinant DNA & gene splicingSlide10
The gene responsible for cystic fibrosis has been identified and it is hoped that, using recombinant DNA technology, it will be possible to transfer a normal copy of the gene into affected cells.
Young man with cystic fibrosis taking medication using a nebuliser.
Wellcome LibrarySlide11
DNA sequencing & gene probesSlide12
DNA sequencing and DNA profiling
DNA sequencing
is used to work out the exact
order of the base pairs in a section of DNA. Knowing the base sequence can be helpful in locating and identifying specific genes.Gene probes can then be made and used to locate these genesSlide13
Gene probes
The search for a particular gene uses a single-stranded piece of DNA called a
gene probe
.Probes are constructed with a radioactive or fluorescent tag so that they can be detected after attaching to the DNA.We know the base sequences in a number of disease-causing genes. Gene probes can detect if these genes are present in individuals being tested.Slide14
DNA profiling & gel electrophoresisSlide15
DNA sequencing & DNA profiling
DNA profiling
is used to identify
individuals Gel electrophoresis is used in DNA profiling.Slide16
Short tandem repeats
Short tandem repeats (STRs) are sequences of non-coding DNA.
They are sections of DNA that make each individual unique
Closely related individuals will share many of the same STRs
STRs are used in DNA profiling to identify individualsSlide17
Gel Electrophoresis
Gel electrophoresis separates
fragments of
DNA using an electric current
.DNA has a slight negative charge. It will migrate towards the positive end of the gel.Smaller fragments move faster through the gel than larger fragments.At the end of the ‘run’ a pattern of bands will be produced. Each band represents a fragment size of DNA from the sample. Different samples will have different patterns.Slide18
Fragment lengths and gel electrophoresisSlide19
Blotting is a method of ‘photographing’ the resulting sequence of DNA fragments once they have gone through the process of gel electrophoresis.
In the example below, what
is the genotype of the
father? Rule out all the mother’s alleles. The ones left are from the father.
DNA blot analysisSlide20
DNA profiling
- summary
Steps in DNA profiling
Collect samples of material containing cellsExtract DNA from samples
Place solution of DNA into gel electrophoresisRun gelProcess gel to see location of DNA bandsPhotograph the gel (DNA or Southern blot)Slide21
Sample
Amelogenin
D3S1358
vWA
FGA
D8S1179
D21S11
D18S51
Victim
XY
14, 15
18, 20
24
13, 16
28, 30.2
14, 15
Suspect
XY
14, 15
15, 18
21, 22
13, 14
30
14, 15
Blood Stain from Crime Scene
XY
14, 15
15, 18
21, 22
13,14
30
14, 15
Capillary electrophoresis
STR profiles are more easily stored and compared
in the form of
numbers and letters rather than pictures
of lines.
Capillary electrophoresis
is a way of collecting numerical data that is plotted on a line graph.
The peaks on the graph represent the different STRsSlide22
Capillary
electrophoresis graphSlide23
Uses of DNA profiling
Identification
Criminals
Victims – crimes, disastersFamily membersSpecies – quarantine, smugglingGenetic differences between populationsInformation is kept in data banks