, Microbiology, Immunity &Forensics
CHE FORENSICS
PCR & DNA
fingerprinting
PCR (polymerase Chain reaction
o replicate
↳ Step in preparation for DNA
profiling . It's needed to
amplify DNA samples.
method
-
-
Prepare vials containing-DNA sample
DNA free -
nucleotides
-DNA primers= short stand complementary to the S'
of DNA end of DNA .
Theatresistant
-
Thermostable DNA polymerase (Tag polymerase) .
Both PCR + Semi-conservative replication
-
Buffer solution DNA nucleotides
use primers. /polymerase .
O These vials are subject to acycle of temp. changes by placing them in a
PCR machine (thermocycle) or water bath
Step 1 : 90-95 % for 305 to break H-bands Separating DNA into 2 stands .
Step 2 : 50-600 for Cos to allow
primers to bind "Annealing
Step 3 : 750 for 1 min = opt temp for Tag polymerase to form
complementary strands
using
free active DNA nucleotides Q BUT heat used to
separate Strands in PCR
DNA helicase in replication.
* Rpt process 35 times
D PCRises higher temp than tempin cells .
DNA
fingeprinting (Profiling
Theory of DNA fingerprinting.
incredibly similar
·
Despite the fact that are exons are , introns are
hypervariable.
↳ due to the of short repeated sequences of nitrogenous bases known as Satellites/short tandem repeats (STR)
presence .
· Number of Satellite (STR) repeats is
unique for each person .
·
So DNA
fingerprinting assumes that ,
apart homidentical twins each ,
individual should have a
unique fingerprint c
diff bands at each locus PROCESS
-crushedirsuT
1 .
A sample of DNA is collected (Blood/hair ... )
. This extracted DNA is
2
ed by PCR.
a
. DNA is cut into
3
fragments using
restriction enzyme e.
4 DNA is loaded tall using
on
agarose get a
micropipette
Selectrophoresis 404 anode (+ ) electrode
DNA-re DNA moves toward
applied
5 DNA is labelled
.
by radioactive material /flourescent sowrenelechic current is
G DNA is viewed /e ① lighte DNA moves faste
by X-ray or light
.
-
, ② diff banding patterns
/DNA profiles
Uses of DNA
fingerprinting jad
.
Child's DNA profile that don't belong to the mother
-
① Disrupted Paternity : bands in the
father E
are compared to the
alleged
-
② Crime Scenes : DNA samples ham crime Scene are
compared to DNA of the suspects .
Similar bands mean similar DNA
fragments . So
they most probably belong to the same person
Call bands in Crime Scene DNA are
present in S2DNA) ↳ continue a theory
③ Ancestral Relationships : DNA from different species is compared . If they have similar bonds
theymost probably
belong to a common ancestor
the more similar the bands -> the more closely related they are
④ Corpsedentity -
NB Process of DNA fingerprinting is not 100% conclusive ?
Why ?
arise
·
It's a multiphasic process , so artifacts might at
any stage.
Identical twins& Closely related individuals
may have similar fingerprints .
The
sample at crime scene are small , distorteda may be contaminated y by other individuals DNA -
to
6So they
might accidently similar a certain suspect's DNA .
N B .
DNA -DNA finger printing I
analyse
We
proteins Proteomics
>
-
②
↳ study of
proteins
.
Mitochondrial DNA/mtDNA - >
only comes from the mother
mother
belong to Surrogate
Surrogacy -
.. somehands
(m+ DNA)
-MEDNA sperm of father N .
B ·
child will inherit the mitochondria hom the mother
①
-
e
-
only Mitochondria
present are the orum
&
in
injected
a which does not enter the
surrogat mid-piece of
spom
g
Denucleation
storum
ovum
upon fertilisation.
bio . mother
* Individual's mitochondria are derived from the
zygote
CHE FORENSICS
PCR & DNA
fingerprinting
PCR (polymerase Chain reaction
o replicate
↳ Step in preparation for DNA
profiling . It's needed to
amplify DNA samples.
method
-
-
Prepare vials containing-DNA sample
DNA free -
nucleotides
-DNA primers= short stand complementary to the S'
of DNA end of DNA .
Theatresistant
-
Thermostable DNA polymerase (Tag polymerase) .
Both PCR + Semi-conservative replication
-
Buffer solution DNA nucleotides
use primers. /polymerase .
O These vials are subject to acycle of temp. changes by placing them in a
PCR machine (thermocycle) or water bath
Step 1 : 90-95 % for 305 to break H-bands Separating DNA into 2 stands .
Step 2 : 50-600 for Cos to allow
primers to bind "Annealing
Step 3 : 750 for 1 min = opt temp for Tag polymerase to form
complementary strands
using
free active DNA nucleotides Q BUT heat used to
separate Strands in PCR
DNA helicase in replication.
* Rpt process 35 times
D PCRises higher temp than tempin cells .
DNA
fingeprinting (Profiling
Theory of DNA fingerprinting.
incredibly similar
·
Despite the fact that are exons are , introns are
hypervariable.
↳ due to the of short repeated sequences of nitrogenous bases known as Satellites/short tandem repeats (STR)
presence .
· Number of Satellite (STR) repeats is
unique for each person .
·
So DNA
fingerprinting assumes that ,
apart homidentical twins each ,
individual should have a
unique fingerprint c
diff bands at each locus PROCESS
-crushedirsuT
1 .
A sample of DNA is collected (Blood/hair ... )
. This extracted DNA is
2
ed by PCR.
a
. DNA is cut into
3
fragments using
restriction enzyme e.
4 DNA is loaded tall using
on
agarose get a
micropipette
Selectrophoresis 404 anode (+ ) electrode
DNA-re DNA moves toward
applied
5 DNA is labelled
.
by radioactive material /flourescent sowrenelechic current is
G DNA is viewed /e ① lighte DNA moves faste
by X-ray or light
.
-
, ② diff banding patterns
/DNA profiles
Uses of DNA
fingerprinting jad
.
Child's DNA profile that don't belong to the mother
-
① Disrupted Paternity : bands in the
father E
are compared to the
alleged
-
② Crime Scenes : DNA samples ham crime Scene are
compared to DNA of the suspects .
Similar bands mean similar DNA
fragments . So
they most probably belong to the same person
Call bands in Crime Scene DNA are
present in S2DNA) ↳ continue a theory
③ Ancestral Relationships : DNA from different species is compared . If they have similar bonds
theymost probably
belong to a common ancestor
the more similar the bands -> the more closely related they are
④ Corpsedentity -
NB Process of DNA fingerprinting is not 100% conclusive ?
Why ?
arise
·
It's a multiphasic process , so artifacts might at
any stage.
Identical twins& Closely related individuals
may have similar fingerprints .
The
sample at crime scene are small , distorteda may be contaminated y by other individuals DNA -
to
6So they
might accidently similar a certain suspect's DNA .
N B .
DNA -DNA finger printing I
analyse
We
proteins Proteomics
>
-
②
↳ study of
proteins
.
Mitochondrial DNA/mtDNA - >
only comes from the mother
mother
belong to Surrogate
Surrogacy -
.. somehands
(m+ DNA)
-MEDNA sperm of father N .
B ·
child will inherit the mitochondria hom the mother
①
-
e
-
only Mitochondria
present are the orum
&
in
injected
a which does not enter the
surrogat mid-piece of
spom
g
Denucleation
storum
ovum
upon fertilisation.
bio . mother
* Individual's mitochondria are derived from the
zygote
