Round Two... A week of re-do's, learning from mistakes, and asking questions.

So this week started with me doing my very first gram staining and trying to identify my unknown. However, I ran into a problem when identifying my unknown the first time. I thought I had gram + cocci, but it turned out that was not correct. I tried gram staining a second time to identify my unknown from the same petrie dish as the first time, but ran into another problem. I had too much of my unknown sample on the slide and it still came out looking like cocci but this time around it was negative. After confirming with Josh that I still did not have it correct. Josh suggested I start again from the very beginning and re-doing my lawn streaking. All this took place on Monday (10-28-2013).

I actually did not re-do my lawn streaking until Wednesday (10-30-2013). The reason behind it was Josh suggested that I incubate this sample over a shorter period of time (one day) rather than a long period of time (three days) like beforehand. After re-doing my lawn streaking and incubating, I started to think about what could have gone wrong with my first sample to keep on coming up incorrect. The first error I thought of was when I was gram staining I was scooping up too much of my unknown on to the inoculating loop before applying it to the slide. Making it hard to find a spot where I could identify my unknown clearly. The second error that could of effected my findings was when I was gram staining; over using the crystal violet and the decolorizer. And the last error that I thought of that could of made a difference was time. Over timing how long, the chemicals stay on the unknown sample on the slide.

Therefore, when I did my gram staining today (10-31-2013) I made sure I only gazed the inoculating loop on top of my unknown. Secondly, I made sure not to over use the crystal violet and the decolorizer and kept a close eye on the time. With making these adjustments, I finally got the correct result. My unknown was gram – bacilli. Once I had the correct answer, I moved on to the next test, which was the oxidase test. My sample came out positive, which led me to do a glucose fermentation test. On Monday (11-4-2013), I get my results for the glucose fermentation test. Blow are pictures of the oxidase test and the glucose fermentation test I did today (10-31-2013).