Bài giảng chủ đề Tin Sinh Học Những điều cơ bản về Tin Sinh Học bằng tiếng Anh. Trong bài giảng này, chúng ta tìm hiểu về những khái niệm cơ bản trong tin sinh học và một số phương pháp giải trình tự (Sequencing methods) cơ bản
Trang 3 Bioinformatics is the application of
information technology
◦ to the management of biological data
◦ to the study of biological problems
◦ to store, retrieve and assist in understanding
biological information
Bioinformatics Biology Medicine
Computer science Maths/physics
Trang 10 Maxam/Gilbert chemical sequencing
Automated sequencing
Nanospore sequencing
Cheap sequencing
Trang 11Maxam-Gilbert sequencing is performed by
chain breakage at specific nucleotides
DMS
G
G G G
FA
G A
G G A G A
A
H
C
T T C T C
C T
H+S
C C C
C
Trang 12Sequencing gels are read from bottom to top (5′ to 3′).
G G+A T+C C
3′
A A G C A A C G T G C A G
Trang 15Template area to be sequenced
-3′ OH TCGACGGGC…
Trang 17 With addition of enzyme (DNA polymerase), the primer is extended until a ddNTP is
encountered
The chain will end with the incorporation of the ddNTP
With the proper dNTP:ddNTP ratio, the
chain will terminate throughout the length
of the template
All terminated chains will end in the ddNTP added to that reaction
Trang 18 The collection of fragments is a sequencing ladder.
The resulting terminated chains are resolved
by electrophoresis
Fragments from each of the four tubes are
placed in four separate gel lanes
Trang 19Sequencing gels are read from bottom to top (5′ to 3′).
G A T C
3′
G G T A A A T C A T G
Trang 20 Cycle sequencing is chain termination
sequencing performed in a thermal cycler
Cycle sequencing requires a heat-stable DNA polymerase
Trang 21 Fluorescent dyes are multicyclic molecules
that absorb and emit fluorescent light at
Trang 22 In dye primer sequencing, the primer
contains fluorescent dye–conjugated
nucleotides, labeling the sequencing ladder
at the 5′ ends of the chains
In dye terminator sequencing, the
fluorescent dye molecules are covalently
attached to the dideoxynucleotides,
labeling the sequencing ladder at the 3′
ends of the chains
ddA
ddA
Trang 23T
G
T
Trang 24G A T C
The DNA ladder is resolved in one gel lane or
in a capillary
Trang 25 The DNA ladder is read on an
electropherogram
Capillary Slab gel
5′ A G T C T G
Electropherogram
Trang 265′ A G T C T G 5′ A G( T/ A ) C T G 5′ A G A C T G
T/T T/A A/A
capillary instruments.
sequence in text and electropherogram form.
Peak patterns reflect mutations or sequence changes.
Trang 28 Scientists needed $3 billion and 13 years to sequence the three billion base pairs encoded in
By 2011, eight years after that first project was completed, the cost of sequencing a human genome had fallen to $5,000, in a process that took just a few weeks.
engineer and the founder of the biotech company Ion Torrent, unveiled an approach that is faster and cheaper still He says his machine will be able to sequence a human genome, some 3.2
$1,000
Trang 30 Genetic information is stored in the order or sequence of nucleotides in DNA.
Trang 32 SeqVerter
DNAclub