DNA Profiling - DNA Sequencing

1. DNA Profiling

2. DNA SEQUENCING
determining the order of the four chemical building
blocks - called "bases" - that make up the DNA
molecule.

3. First-
generation
sequencing
technology
: Maxam-
Gilbert
method and
Sanger
method
SECOND -generation sequencing technology

4. https://www.youtube.com/watch?v=_B5Dj8PL4E0
Maxam–Gilbert DNA Sequencing Method Animation

5. VAC course: Basics of Bioinformatics 23rd-26th August, 20223
Maxam-Gilbert Sequencing Method:
Developed by Allan Maxam and Walter
Gilbert in the late 1970s
Chemical Cleavage: The DNA molecule is
first chemically modified at specific bases
to create cleavage points. Four different
reactions are performed, each targeting a
specific type of base (A+G, C, G, T).
Fragment Separation: The labeled
fragments are separated by gel
electrophoresis.
Sequence Determination: The sequence of
the DNA is determined by reading the
order of bands on the gel. Each band
corresponds to a cleavage site, revealing the
positions of the specific modified bases and
their respective sequence positions in the
DNA.

6. How Sanger Sequencing Works? (Classic Sanger Method)
https://www.youtube.com/watch?v=-QIMkQ4E_wE

7. VAC course: Basics of Bioinformatics 23rd-26th August, 20223
Sanger Sequencing Method:
The Sanger sequencing method, developed by Frederick
Sanger around the same time, became more widely adopted
due to its technical advantages.
1.Primer Annealing: A short DNA primer is annealed to
the single-stranded DNA template. DNA synthesis begins
from the primer using a DNA polymerase enzyme.
2.DNA Synthesis with Chain Terminators: DNA synthesis
is carried out using a mix of regular deoxynucleotides
(dNTPs) and chain-terminating dideoxynucleotides
(ddNTPs). The ddNTPs lack a 3' hydroxyl group,
preventing further elongation of the DNA
3.Fragment Separation: The DNA synthesis reactions
generate a series of fragments of varying lengths, each
terminating with a ddNTP. The fragments are separated
by gel electrophoresis, similar to the Maxam-Gilbert
method.
4.Sequence Determination: The sequence is deduced by
analyzing the order of bands on the gel, with the last band
in each lane indicating the nucleotide at the corresponding
position in the DNA sequence.

8. VAC course: Basics of Bioinformatics 23rd-26th August, 20223
•Principle: Both methods rely on chemical modifications and
subsequent separation to determine DNA sequence.
•Read Length: Sanger sequencing generally provided longer read
lengths compared to Maxam-Gilbert sequencing.
•Throughput: Sanger sequencing was more amenable to automation and
higher throughput due to the use of a single reaction mix with chain-
terminating nucleotides.
•Labor Intensity: Maxam-Gilbert sequencing involved more complex
chemical reactions and separate reactions for each base type, making it
more labor-intensive.
•Widespread Adoption: Sanger sequencing gained wider adoption due to
its simpler reaction setup and more streamlined process.
•Advancement: Both methods laid the groundwork for DNA sequencing
but have been largely replaced by high-throughput Next-Generation
Sequencing (NGS) methods due to their speed, scalability, and lower c

9. Next Generation Sequencing - A Step-By-Step Guide to DNA Sequencing
https://www.youtube.com/watch?v=WKAUtJQ69n8

10. Massively Parallel Sequencing
https://www.youtube.com/watch?v=CDUF5VKzQLo

11. Introduction to nanopore sequencing
https://www.youtube.com/watch?v=qzusVw4Dp8w

12. Unit 4: DNA database and quality assurance
• NDNAD, CODIS, and other databases,
• DNA Lab Quality Assurance and Quality Control, Forensic DNA
Advisory Groups: US DOJ, SWGDAM, AAFS, ENFSI DNA WG, and
ISFG DNA. National and International accredited bodies, quality
standards, certification, and legal Admissibility of DNA Evidence.
• National bodies for DNA profiling: CDFD, CCMB, LaCONES.

13. http://www.cdfd.org.in/index.html

14. http://www.cdfd.org.in/index.html

16. Centre for DNA Fingerprinting and Diagnostics (CDFD)
Documentary

17. https://www.ccmb.res.in/

19. https://www.ccmb.res.in/Service/Molecular-Diagnosis

20. https://e-portal.ccmb.res.in/lacones/lacones.html

23. VAC course: Basics of Bioinformatics 23rd-26th August, 20223
https://www.icmr.gov.in/cnextgenseq.html

26. Based on 19 studies review
• DNA databases are an effective deterrence
and detection tool
• DNA databases are more effective in studying
the crimes committed by unidentified
offenders than other criminological data
sources
• Combining the DNA database and the police
recorded crime database gives a more
complete view on criminal networks than the
police database alone
• DNA databases do increase the probability of
identification, arrest and prosecution in cases
of property crimes

27. NDNAD , UK 1995

30. How the FBI's DNA database called CODIS

32. Private database: Bode dbSEARCH

33. direct matching between known
and unknown sample profiles
profiles from missing persons
and their relatives
unidentified human remains

34. Current scenario in India
• huge requirement for these types of
databases which may help in stopping
different types of fraud like ration
card fraud, voter identity card fraud,
driving license fraud etc
• The database may help the Indian
police to differentiate the criminals
and non criminals.

35. https://prsindia.org/billtrack/the-dna-technology-use-
and-application-regulation-bill-2019

36. • The DNA Technology (Use and
Application) Regulation Bill, 2019
was introduced in Lok Sabha by the
Minister for Science and
Technology, Mr. Harsh Vardhan, on
July 8, 2019.
• Use of DNA Data: offences under
the Indian Penal Code, 1860, and
for civil matters such as paternity
suits.
• DNA testing for matters related
to establishment of individual
identity.

37. Collection of DNA
arrested persons: written consent if the offence carries a
punishment of up to seven years
more than seven years of imprisonment or death,
consent is not required
person is a victim, or relative of a missing person, or a
minor or disabled person, the authorities are required
to obtain the written consent.
Magistrate who may order

38. DNA Data Bank
National DNA Data Bank and Regional DNA Data
Banks, for every state, or two or more states
maintain indices for the following categories of
data: (i) a crime scene index, (ii) a suspects’ or
undertrials’ index, (iii) an offenders’ index, (iv)
a missing persons’ index, and (v) an unknown
deceased persons’ index.

39. Removal of DNA profiles
(i) of a suspect if a police report is filed or
court order given
(ii) of an undertrial if a court order is given
iii)on written request, for persons who are
not a suspect, offender or undertrial, from
the crime scene or missing persons’ index.

41. This Photo by Unknown Author is licensed under CC BY-SA