Microarray Experiment Overview: mRNA to cDNA

In our example, we’ll ask the question, Do tumor cells express specific sets of genes?

First, mRNA is extracted from cells. One sample is taken from tumor cells and another from normal cells. The mRNA is then converted to complementary DNA, or cDNA, using the enzyme reverse transcriptase.

A sequence of illustrations showing a tumor with an arrow pointing to a partially filled test tube labeled m-R-N-A. An arrow labeled Reverse transcriptase points to a second partially filled test tube labeled c-D-N-A. A cutaway shows a curly red strand. Below it, the same sequence is repeated starting from a normal cell but the c-D-N-A strand is green.