What is the first step in making an agar plate?

The first step in making an agar plate is to pour hot agar jelly into shallow Petri dishes. This process involves preparing the agar medium, which is typically made by dissolving agar powder in boiling water mixed with nutrients. Once the agar is in a liquid state, it is poured into the Petri dishes while it is still hot and fluid. This allows the agar to evenly spread across the bottom of the dish, and once it cools, it solidifies into a gel-like medium that can be used for culturing microorganisms.

This step is crucial for creating a suitable environment for bacteria to grow, as the agar provides a stable surface with nutrients that will support microbial life. Other steps in the agar plate preparation process, such as allowing the agar to cool completely, adding nutrients separately, or inoculating with bacteria, cannot occur until this initial step of pouring the agar is completed.