How to use the autoclave

Today was the first day to conduct an experiment. We had to make agar medium solutions and sterilize them for storage so we may use them in the future. We first learned what agar solution was and what kinda of different ones there were for specific microbes. We were given a lecture on the medium and how to make it and then proceeded to do so.

We were given two options for the agar mediums and I chose the slightly more complicated one as the mixture was not an already pre measured and scaled mix for making mediums but we had to measure what ingredients went in, mix the right amount of distilled water, and correct the pH level for ideal growth conditions.

Also I made a significant mistake when using the pH controller, as I misplaced the airtight cap that goes between the tube and the twist cap. It was contaminated and so not deemed safe to place back and so discarded.

After that, we used an stirrer and a microwave to make a homogeneous mixture, while taking care not to overspill the now heated mixture. After that, we sealed the flasks airtight and placed them in the autoclave. One thing to note is that we do not possess an autoclave so we are currently using a pressure cooker. We followed additional instructions such as making sure the flasks do not tip over while being sterilized and to wait at least 30minutes after the pressure cooker starts steaming.

After that we marked our petri dishes and then proceeded to pour them without contamination and then store them. It was a successful and important first step towards our journey.

We also accidentally opened the petri dish and possibly contaminated it. So instead of throwing it out, I suggested we divide the circle space equally and without any further preparation, imprint our bare fingers on it just to see what happens. In retrospect that might not have been a very safe or controlled experiment however the risk was minial that we would somehow create a highly contagious anti biotic resistant lifeform that would kill us all so that was cool.

The results were interesting for me as I seemed to have had a mostly uniform sort of growth of a singular species, even though I did press down on the most area. Our colleagues were equally surprised as they thought their hands were clean since we washed out hands prior to the experiment and kept them in gloves. It was a learning valuable experiment for the class and I am glad we can make mistakes to try new things.