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Pyrosequencing
By: Qadardana kakar
BS Biotechnology
7th semester
Aims/ Objective
 The Aim of presentation is to explain the process of pyrosequencing.
Content
 DNA sequencing
 Pyrosequencing
 Principle
 Methodology
 Application of pyrosequencing
DNA sequencing
 Technology that is used to determine the order of the four bases adenine, thymine, guanine,
and cytosine in a strand of DNA.
1. Maxam – Gilbert sequencing
 2. Chain-termination methods (Sanger sequencing)
 3. Dye-terminator sequencing
 4. Pyrosequencing (modern techniques)
Pyrosequencing
Pyrosequencing technology is a recently established non electrophoretic,
sequencing-by-synthesis technique which uses an enzymatic system based on luciferase to
monitor DNA production .
Principle :
(DNA)n +dXTP DNA polymerase (DNA)n+1 + PPi
PPi+ APS ATP Sufurylase ATP + SO4
2_
ATP + Luciferin+ O2 Luciferase AMP + PPi + Oxyluciferin + CO2 + Light
ATP + dXTP Apyrase ADP+ dXDP + 2Pi
ADP + dXDP Apyrase AMP + dXMP + 2Pi (Wong et al., 1991)
Methodology
1. DNA fragmentation
2. Adapter binding to ends of DNA fragments.
3. Denaturation of fragments
4. Fix to a solid surface, Sepharose beads or streptavidin-coated magnetic beads
( beads which are surrounded by single stranded sequences)
5. Beads has sequences complementary to adapter sequences.
1. Methodology
 Load the beads into sequencing wells (small DNA grooves).
 Chemical process
I. Add DNA polymerase and single dNTP (polymerization)
II. Add sulfurylase and APS ( ATP synthesis)
III. Add luciferin and luciferase (light production)
IV. Detection ( light sensor)
V. Washing or add enzyme apyrase enzyme.
Application of Pyrosequencing
 Pyrosequencing has shown well performance in determination of complex DNA structure
such as

 cDNA analysis, mutation detection

 Re-sequencing of diseases linked genes,
 viral typing, bacterial typing, and SNPs.