Zoo blot

A zoo blot is a DNA hybridization technique that demonstrates the similarity between specific DNA sequences.

In order to understand the degree to which a particular gene is similar from species to species, DNA preparations from a set of species is isolated and spread over a surface. The sequence of interest is labeled and allowed to hybridize to the prepared DNA. Usually, the labeled DNA is marked with a radioactive isotope of phosphorous. The hybridization is a process that happens spontaneously: DNA pairs with complementry strands. The hybridization, however, is not perfect.

The hybridization of two strands will happen even when the strands are similar but not identical. This procedure is used to detect similar or exact relationships between the DNA in question and other organisms, so the technique takes advantage of non-exact hybridization.