This document provides an overview of DNA microarray technology. It discusses the historical background beginning in the 1970s with Southern blotting and the development of microarrays in the 1980s. The key principles are that DNA microarrays allow analysis of thousands of genes simultaneously and efficiently through orderly arrangement of DNA sequences on a solid surface like glass. The main steps involve preparing the microarray slide through various methods, performing experiments with sample mRNA, fluorescence scanning, and data analysis to understand gene expression patterns. DNA microarray technology has wide applications in studying diseases, toxicology, and stem cell research.

1. DNA Microarray Technology
Under the guidance of
Dr .Manjunath
Ankitha Hirematha
3rd sem, MSc.,
Dept. of Biotechnology
Kuvempu university.

2. CONTENTS
• Introduction
• Historical Background
• Principle
• Overview steps
• Preparation of slide
• Microarray scanning
• Data analysis and normalization

3. DNA Microarray Technology
To analyze the expression of thousands of genes in
single reaction, very quickly and in an efficient manner.

 To understand the genetic causes for the abnormal
functioning of the human body.
To understand which genes are active and which genes
are inactive in different cell types.

5. What is DNA Microarray Technology ?
It is “an orderly arrangement of thousands of
identified sequenced genes printed on an
impermeable solid support , usually glass, silicon
chips or nylon membrane”.
 DNA microarray chips are also known as DNA chips, DNA
arrays, or biochips.

6. Historical background :
Sir Edwin Southern
• Southern blotting was developed in the year 1975.
• The concept of DNA microarrays began in the mid
1980s.
Sir Steve Fodor
• Pin based robotic system was developed by
Lehrach’s group in 1990.
• Steve Fodor developed scanner for reading the
output.
•“Quantitative
Monitoring
of
Gene
Expression Patterns with a complementary
DNA microarray”
reported by Patrick
Brown, Mark Schena and colleagues in
Science (1995).
•Mark Schena was proclaimed as the
“Father of Microarray Technology”.
Sir Patrick
Brown
Mark Schena

7. Principle of DNA Microarray:

8. An overview of steps involved in DNA Microarray

9. Preparation of DNA Microarray Slide :
 The solid supports used are glass, silicon or nylon membranes
Length of slide is 25 X75mm
 Within the area of 3.6cm2 , 10,000 to 20,000 spots(genes)
Diameter of spot is 50-150μm
 Distance between the spots is 200-250 μm.
Fabrication
• Photolithography
• Robot spotting
• Inkjet

10. Photolithography

11. Robot Spotting

12. I
n
k
j
e
t
s
p
o
t
t
i
n
g

13. Performing DNA Microarray Experiment
Eg. Saccharomyces cerevisiae
O2
O2
Centrifuge
Supernatant is discarded
Add extraction buffer

14. Remove that buffer containing mRNA
and place in fresh tube
AAAAAAAAAAA
AAAAAAAAAAA
AAAAAAAAAAA
AAAAAAAAAAA
AAAAAAAAAAA
AAAAAAAAAAA
Reverse Transcription
TTTTTTTTTTTTT
TTTTTTTTTTTTT
TTTTTTTTTTTTT
c DNA
TTTTTTTTTTTTT
TTTTTTTTTTTTT
TTTTTTTTTTTTT
Mix

15. ATGC
ATGC
ATGC
GATC
GATC
GATC
When
When
laser comes,
laser comes,
Merged image :
TCAG
TCAG
TCAG

16. DNA Microarray Scanner
• Fluorescent intensity is measured
“Normalization means to adjust the
microarray data for effects which arise from
variation in the technology”.

17. Applications
• Gene expresion profiling, SNP detection, human diseases etc..
• IPSC (Induced Pleuripotent Stem Cell) cell lines are validated and
monitored.
• Toxic studies

18. CONCLUSION
Since this DNA microarray technology is used for
the analysis of expression of thousands of genes at
once, and has wide applications in in analyzing
various diseases. It is one of the smartest technique.

19. REFERENCES
•Tim Lenoir ,Eric Giannella (2006) The emergence and diffusion of DNA microarray
technology. Journal of Biomedical Discovery and Collaboration(JBDC). 1:11
•Samuel K. Moore (2001) Biochips are now a critical tool for analyzing the human
genome--and a lucrative product attracting technology giants. IEEE spectrum
• http://www.premierbiosoft.com/tech_notes/microarray.html
•http://www.genome.gov/10000533
•http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1590052/
•http://www.medscape.com/viewarticle/543871_2
•http://en.wikipedia.org/wiki/DNA_microarray#History
•http://grf.lshtm.ac.uk/microarrayoverview.htm#m1
•http://www.ncbi.nlm.nih.gov/About/primer/microarrays.html
•http://www.digizyme.com/portfolio/microarraysfab/photolith.html

20. Thank You