This week. Dec 10/12

This week is finally... almost over, along with finals. I am still surprise of how much I've learned in these past few weeks during my internship at the biology lab in Phoenix College. I've learned to do Gram Staining, the methodology behind making media and streaking a plate with a bacteria sample.
Gram Stain is simple and yet easy to mess up, specially when its the first time doing it. After three or four trials I started to get the hang of it. There are four major steps during staining; first crystal violet is applied for 30 seconds, then iodine is added for 60 seconds.  A decolorizer is then added to wash away the crystal violet, if it's a Gram negative bacteria, it will not wash it away if its a Gram positive bacteria. The tricky part with this step is that if the decolorizer is left for too long on, the crystal violet gets washed away from both Gram positive and Gram negative bacteria, but if not left for enough time a Gram negative bacteria might have purple or blue dyed bacteria as well. At the end Safranin is added for about 30 seconds. Between all steps the sample must be rinsed with water for about 5 seconds.
 Just yesterday I was able to perform a Gram Stain on a bacteria that showed antibiotic characteristics. The sample turned out to look like rods which indicates bacili and it was also Gram Positive. The image shows what I saw in the microscope.

I also made my own Macconkey agar, with the instructions of Kimberly, all I know about her is that she works at the lab but I am very thankful. Fun fact, macconkey agar kind of smells like dog food so during the process of making it I remember a German shepherd I had years ago. Hopefully I will be able to use these plates to cultivate some agrobacterium for my research project. Right now I have only written my protocol and cultivated 8 plates with what, after three tests (Gram stain, catalase test and oxidase test, I believe to be Rhizobium. Rhizobium is a plant growth promoting rhizobacteria, or PGPR, that a Gram Negative bacili. It is also positive for a Catalase test and Oxidase test.  I used 4 plates with TSA media and 4 plates with Macconkey media. I have placed those plates in an incubator and I'm just in the waiting processes to see if anything grows, fingers crossed.