Expressed sequence tag

Imagine you are helping your parents bake a cake. You need a recipe to know what ingredients and steps are needed to make the cake. The recipe tells you what ingredients to use and in what order to mix them. In the same way, scientists need a recipe to understand how a living thing works. This recipe is called DNA.

But how do we read the DNA recipe? Scientists use a special method called expressed sequence tagging (EST). An EST is a small part of DNA that tells us how to make a specific protein. Think of a protein as a special ingredient in the cake -- without it, the cake wouldn't be the same.

So, scientists take a sample of DNA and break it down into smaller pieces, called fragments. They read each fragment to find the ESTs. Think of each fragment as a page in a big book of recipes, and each EST as a sentence in that page that tells us how to make a protein. By finding all the ESTs in the sample, scientists can understand the full recipe, or DNA sequence, of the living thing.

Overall, EST is a way for scientists to decode the "recipe" of DNA, just as we use a recipe to make a cake. By understanding a living thing's DNA recipe, scientists can learn more about how it works and what makes it unique.