Microarrays are essential tools in molecular biology for analyzing gene expression and genomic features, including various types such as oligonucleotide, cDNA, protein, tissue, CGH, and SNP microarrays. Each type serves specific functions, from gene profiling and mutation analysis to cancer detection and personalized medicine. Overall, they offer a diverse range of applications across research, diagnostics, and biotechnology sectors.

1. MICROARRAYS
HARIPRIYA U VARMA
2ND
MSC BIOTECHNOLOGY

2. INTRODUCTION
 Microarrays are the
powerful tools in
molecular biology for
studying gene
expression and other
genomic features.
 They allow
researchers to
analyze thousands of
genes or DNA
sequences
simultaneously.

3. OLIGONUCLEOTIDE MICROARRAYS
 Oligonucleotide microarrays consists of short, single-stranded DNA
probes attached to a solid surface.
 These probes are designed to hybridize with complementary
sequences in target samples, such as mRNA or genomic DNA.
1) HIGH SPECIFICITY
Oligonucleotides provide high specificity due to their short length,
minimizing cross hybridization.
2) Versatile applications
Oligonucleotide microarrays are suitable for gene expression profiling,
genotyping and mutation analysis.
3) Widely used
They are commonly used in research, diagnostics, and drug development

4. cDNA microarrays
 cDNA microarrays utilize complementary DNA (cDNA)
probes, synthesized from mRNA.
 This probes are attached to a solid surface and hybridized
with target mRNA from a sample.
1) Gene expression profiling
cDNA microarrays are primarily used to study gene expression
changes in response to different stimuli or conditions.
2) Advantages
They offer high sensitivity and are relatively inexpensive
compared to other microarrays platforms.
3) Limitations
cDNA microarrays can suffer from cross-hybridization issues
and are less specific than oligonucleotide arrays.

6. PROTEIN MICROARRAYS
 Protein microarrays are a specialized type of microarrays
used to analyze protein interactions, activity, and abundance.
 They typically involve immobilizing proteins on a surface and
then exposing them to a labeled target, such as antibodies or
small antibodies or small molecules.
1) Protein immobilization
Proteins are immobilized on to a surface, such as a glass slide or
a membrane.
2) Target interaction
The immobilized proteins are then exposed to a labeled target,
which may be antibodies, small molecules, or other proteins.
3) Detection
Bound targets are detected using a suitable signal, such as
fluorescence or chemiluminescence.

8. Tissue microarrays
 Tissue microarrays (TMAs) are specialized microarrays
used to analyze multiple tissue samples on a single slide.
 TMAs are created by extracting small cores of tissues
from multiple donors and arranging them in a grid-like
pattern on a single slide.
1) high-throughput analysis
TMAs allow for the simultaneous analysis of hundreds or
even thousands of tissue samples, providing a cost-
effective and efficient way to study tissue heterogeneity
and disease progression.
2) Improved efficiency
TMAs eliminate the need to process multiple individual
slides, saving time and resources.

10. Comparative genomic hybridization
(cgh) microarrays
 CGH microarrays are used to detect copy number
variations (CNVs)in DNA.
 They compare the genomic DNA from a test sample to a
reference sample, allowing researchers to identify gains
or loses of DNA segments.
1) Cancer detection
CGH microarrays are commonly used in cancer research to
identify genomic alterations associated with tumorigenesis.
2) Developmental disorders
They can also be used to detect CNVs associated with
developmental disorders, such as autism as autism
spectrum disorder.

11. Single nucleotide polymorphism (snp)
microarrays
 SNP microarrays are designed to detect single
nucleotide polymorphisms (SNP), which are
variations in the DNA sequence that occur at a
single nucleotide.
1) Disease associated studies
SNP microarrays can be used to identify SNPs that are
associated with an increased risk of developing a
particular disease.
2) Pharmacogenomics
They can also be used to identify SNPs that influence
an individual’s response to drugs, leading to
personalized medicine.

13. conclusion
 Microarrays are
powerful tools with a
wide range of
applications in
molecular biology
and biomedical
research.
 They are used in
various various fields,
including drug
discovery,
diagnostics,
personalized
medicine and
agricultural
biotechnology.