Microarray

A microarray is a high-throughput technique used to measure the expression of thousands of genes at once. It allows researchers to compare gene expression across different samples or conditions.

How it works:

Microarrays consist of a solid surface (usually a glass slide) with thousands of DNA probes fixed to specific spots. mRNA is extracted from cells and converted into labeled cDNA using reverse transcription. The labeled cDNA is then applied to the microarray. If the cDNA binds to a complementary DNA probe on the array, it will remain attached. The array is scanned to detect fluorescence at each spot, which corresponds to the expression level of a specific gene.

Applications:

• Comparing gene expression between healthy and diseased tissues

• Identifying genes involved in specific cellular responses

• Diagnosing diseases based on gene expression profiles

• Studying patterns of gene regulation

How to interpret data:

Microarray data is typically shown as a heat map, where each spot or color indicates the level of gene expression. Red might indicate high expression, green low expression, and black no change. Software is used to quantify and compare expression across conditions.