The Contaminating Menace

By Jessica Bauer

Going into lab last week I was thrilled to check on my plates and see how my little phages were doing. I had just done my Phage Titer Assay test and found that my -1 dilution had a beautiful arrangement of mostly plaques with some M. smegmatis found in between them. The class before, I had made Medium-Titer-Lysate from my beautiful plate and had plated my dilutions up to the -7. That day going into lab, I was excited to see my results and get started on harvesting more and more of my plaques. Unfortunately, that excitement soon diminished.

As soon as I saw my plates I knew something was wrong. My plaques were clear and small, yet the plaques found on my 0 dilution, pure MTL, were odd looking. There was larger cloudy ones and then also a whole group of small cloudy ones around the outside of the plate. What was going on? As I looked at my further dilutions the mystery continued. The -1, -2, and -3 dilutions all had this strange flowery look to them. They looked nothing like the small, clear plaques I was used to seeing. Also, as I opened my plate I was met with a shine that I knew could not be from the normal M. smegmatis.  As I moved on to the -4 and -5 plates I was happy to finally see my small, clear plaques coming back, but unfortunately there was not nearly enough to have a perfect web and move on in lab.

I decided I had to try and get rid of this strange substance. So, I filtered my MTL solution again with a filter and syringe, I got new top agar and new phage buffer and made sure I stayed closer to the bunsen burner then ever before. I plated my dilutions again and thought I had gotten rid of this contamination menace for good. Sadly I was wrong.

The next day in lab upon examining my plates, I found the same thing. The smaller dilutions were covered in this flowery substance and obstructing the view of my plaques and M. smeg.  What could it be this time? I had no idea. Again, I filtered the MTL and used new phage buffer and top agar. I even went as far as to wipe down all the micropippetters with ethanol and made sure to use sterile pipettes when taking liquid out of larger tubes. I plated my dilutions for a third time and  left lab feeling confident that this time I would be rid of this contamination for good.

I was wrong. My third round of dilutions were infected with this contamination just like the first. At his point I was done, there was nothing more I could do. This contamination had ruined my wonderful plaques and MTL solution. All I could do was throw it all away, along with my hopes of finishing early, and start all the way back from performing the Phage Titer Assay test with a new plaque.

I never found out how this dreaded contamination got into my plaques and destroyed all my progress. It will always be a mystery. I just hope that it does not happen to anyone else, because this contamination is a menace. If by chance it does happen, good luck getting rid of it, it likes to stick around for good.

Advertisements
This entry was posted in From the Phage Hunters. Bookmark the permalink.

One Response to The Contaminating Menace

  1. Pingback: The Contaminating Menace | jhublogs

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s