S-Stem Scholar Anthony Luna's Blog

A bit belated, but yesterday in lab Shawn and I made more dilutions of hydrogen peroxide 30% and TGY in preparation for the growth curves we anticipate to do on Friday and Saturday dealing with D. rad and D. pima . It is interesting though because when looking at the results of our previous growth curve we ran last week on D. pima our results were quite inconsistent in terms of the growth rates expressed from the different ratios of our dilutions. We hypothesized that as our dilutions with a greater ratio of TGY to hydrogen peroxide 30% the growth of D. pima would rise. However, that was not the case. In contrast, D. rad's growth was consistent in all of the readings with no inconsistencies. 

In today's lab, Shawn and I made 500mL of TGY (Broth) and TGY (Agar). During our time making the medium, Shawn brought to my attention an imperative step I was missing in my protocol! That was before we add any of the substances to our flask we must first measure and pour half the desired volume in our flask (250mL). Very thankful he brought that to my attention so moving forward I won't have any errors in regards to volume. Another task I performed today was gram staining Deinococcus Radiodurans (D. rad) however this time I wasn't picking my colony from a plate instead I picked it from Broth. The results I received weren't as favorable as I was anticipating due to the fact there were some abnormalities present. D. rad came out gram-positive (purple) instead of gram-negative (pink) which is how D. rad should stain. In addition, I believe possible contamination was present due to spherical gram-positive artifacts or error in my alcohol prep.

Today, I had the opportunity to assist Shawn, Kristin Sr., and April in pipetting in order to make dilutions consisting of Hydrogen peroxide and TGY (Medium).  They were making dilutions for Deinococcus Pima in the ratio of (1:6000) and Deinococcus Radiodurans in the ratio of (1:2000).