Summer Session-A Little Housekeeping

Hello! Welcome back.

This week, I reversed course a little and cultured some Pseudomonas aeruginosa; I then performed an extraction on this little gram negative biofilm-former using my gram positive extraction protocol, just to see if it would succeed at producing DNA. Why? You may recall that this strain was the only gram negative strain I had difficulty extracting DNA from last semester, and you may also recall that my primers were unsuccessful at amplification during last semester's PCRs as well.

After performing the boiling extraction, I ran my standard gel protocol on the sample and was pleased to find that I had visible banding present under UV. Picture below:

(Photo: Four wells, each with P. aeruginosa; wells show different concentrations of sample.)

This was good news, of course, because it allowed me to proceed with a PCR using the primers I have been testing. To date, all of the bacterial species I have PCR-tested using this particular primer set have resulted in amplified DNA post-extraction--- except for P. aeruginosa. This negative result has been gnawing at me for some time, so anything that gets me closer to wrapping up that loose end is a positive, welcome turn.

So I ran a PCR and then checked the sample using my standard gel. The photo below is what resulted.

So it appears that I got DNA. It's not pretty, but given that I blew up the cells using a boiling extraction, that is to be expected.

That's it for this week. See you on my next blog!