introduction

Introduction

Most genes are present in the same quantity in every cell - namely, one copy per haploid cell or two copies per diploid cell.

What genes make an exception to this rule?

However, only a small percentage of the genome is expressed in each cell, and the level at which a gene is expressed can vary widely.

Gene expression patterns vary from cell type to cell type (e.g. neurons vs. hepatocytes).
Even within the same cell, gene expression levels may vary as the cell responds to changes in physiological circumstances.

Various techniques can be used to detect genes and monitor their expression. These techniques use DNA, RNA or Proteins as the biological material for analysis.

In this tutorial we will describe each method and will discuss its relative pros and cons.

Choose a method
DNA Analysis	RNA Analysis	Protein Analysis
Southern blot PCR Sequencing Chromosomal In-situ hybridization	Northern blot RT-PCR RNA In-situ hybridization DNA microarrays	Western blot Immunohistochemistry