Chromosome Banding A gene is a functional unit of DNA, and your DNA is organized onto chromosomes. Chromosome banding is a little like tie-dying your chromosomes. A chromosome is a unit of tightly-packed DNA. DNA has to wrap tightly around itself, because you have quite a lot of it. In fact, if you unrolled all the DNA in a single one of your cells, it would be about three meters long. Humans have 46 chromosomes - 23 from Mom and 23 from Dad. Chromosome-bands In chromosome banding, we treat chromosomes with chemicals to stain them and learn about a chromosome by how it stains. There are several different types of stains we can use. There are several types of chromosome banding. Here, we will list a few of the most common types. G-banding uses a stain called Giemsa stain. G-banding gives you a series of light and dark stripes along the length of the chromosome. We will discuss G-banding in the most detail, because you will likely see G-banding if you take a genetics...
