DNA Microarrays

Introduction

DNA Microarrays are high-throughput technology used to analyze gene expression, detect mutations, and study genetic variations. They allow the simultaneous analysis of thousands of genes by hybridizing labeled nucleic acids to immobilized DNA probes.

Steps in DNA Microarray Analysis

1 Sample Preparation – Extract RNA or DNA from the sample.
2 Labeling – Convert RNA into cDNA and label with fluorescent dyes.
3 Hybridization – Apply the labeled sample onto the microarray chip.
4 Washing – Remove unbound sequences.
5 Detection & Analysis – Use a laser scanner to measure fluorescence and analyze gene expression levels.

Types of DNA Microarrays

• cDNA Microarrays – Use complementary DNA (cDNA) probes.
• Oligonucleotide Microarrays – Use synthetic oligonucleotide probes.
• SNP Microarrays – Detect single nucleotide polymorphisms (SNPs).
• Tiling Microarrays – Cover entire genomic regions for epigenetic studies.

Applications of DNA Microarrays

✅ Gene expression profiling – Identify genes activated in diseases.
✅ Genotyping – Detect genetic mutations and SNPs.
✅ Cancer research – Identify tumor-specific genes.
✅ Drug discovery – Analyze drug effects on gene expression.

Advantages of DNA Microarrays

✔️ High-throughput analysis of thousands of genes.
✔️ Provides comprehensive gene expression data.

Limitations of DNA Microarrays

❌ Requires prior knowledge of sequences.
❌ Less accurate than sequencing technologies like RNA-Seq.