Its a advance technique to check whether gene is mutated or normal.

2.  INTRODUCTION
 PRINCIPLE
 APPLICATIONS
 ADVANTAGES
 LIMITATIONS
 CONCLUSION
 REFERENCE
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3. DEFINITION : A DNA microarray (also known as
DNA Chips or biochip) is a collection of
microscopic DNA spots attached to a solid surface.
Each DNA spot contains Pico moles of a specific
DNA sequences, known as probes.
HISTORY: Microarray technology evolved from
Southern blotting. The concept of microarrays was
first proposed in the 1980s by Augenlicht and his
colleagues.
The use of miniaturized microarrays for gene
expression profiling was first reported in 1995,
and a complete eukaryotic genome(
Saccharomyces cerevisiae) on a microarray was
published in 1997.
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4. a) A DNA chip can be
manufactured to
contain hundreds of
thousands of synthetic
single stranded DNA
sequences.
b) Unknown DNA from a
patient is separated
into single strands,
enzymatically cut and
labelled with a
fluorescent dye.
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5. b) The unknown DNA is inserted
into the allowed to hybridize
with the DNA on the chip.
d) The tagged DNA will bind
only to the complementary DNA
on the chip. The bound DNA will
be detected by its fluorescent
dye and analysed by a
computer. The red light is a
gene expressed in normal cells;
green is a mutated gene
expressed in tumour cells; and
yellow in both cells.
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6.  The principle of DNA microarrays lies on the
hybridisation between the nucleotide. Using this
technology the presence of one genomic or cDNA
sequence in 1,00,000 or more sequences can be
screened in a single hybridization.
 The property of complementary nucleic acid
sequences is to specifically pair with each other by
forming hydrogen bonds between complementary
nucleotide base pairs.
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8. 3. Reverse
Transcription
4. Labelling
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9. 5. Hybridisation
6. Scanning
7. Normalization
and analysis
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11.  Discovery of drugs
 Diagnostics and
genetic engineering
 Proteomics
 DNA sequencing
 Gene expression
profiling
 Toxicological research
 Early detection of oral
precancerous lesions
 In Cancer
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12.  Provides data for thousands of genes.
 One experiment instead of many.
 Fast and easy to obtain results.
 Huge step closer to discovering cures for diseases
and cancer.
 Different parts of DNA can be used to study gene
expression.
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13.  Expensive to create.
 The production of too many results at a time
requires long time for analysis, which quite
complex in nature.
 DNA chips don’t have very shelf life, which proves
to be another major disadvantage of the
technology.
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14. DNA Microarray are one of the most effective
invention ever developed. It is a test that allows for
the comparison of thousands of genes at once.
Microarray technology uses chips with attached DNA
sequences as probes for genes expression.
Any DNA in the sample that is complementary to a
probe sequence will become bound to the chip. The
microarray chip can hold sequences from every gene
in the entire genome and the expression of every
gene can be studied simultaneously.
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