DNA Microarray Technology
Under the guidance of
3rd sem, MSc.,
Dept. of Biotechnology
• Historical Background
• Overview steps
• Preparation of slide
• Microarray scanning
• Data analysis and normalization
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.
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.
Historical background :
Sir Edwin Southern
• Southern blotting was developed in the year 1975.
• The concept of DNA microarrays began in the mid
Sir Steve Fodor
• Pin based robotic system was developed by
Lehrach’s group in 1990.
• Steve Fodor developed scanner for reading the
Expression Patterns with a complementary
reported by Patrick
Brown, Mark Schena and colleagues in
•Mark Schena was proclaimed as the
“Father of Microarray Technology”.
An overview of steps involved in DNA Microarray
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.
• Robot spotting
Performing DNA Microarray Experiment
Eg. Saccharomyces cerevisiae
Supernatant is discarded
Add extraction buffer
Remove that buffer containing mRNA
and place in fresh tube
Merged image :
DNA Microarray Scanner
• Fluorescent intensity is measured
“Normalization means to adjust the
microarray data for effects which arise from
variation in the technology”.
• Gene expresion profiling, SNP detection, human diseases etc..
• IPSC (Induced Pleuripotent Stem Cell) cell lines are validated and
• Toxic studies
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.
•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