Tag: non restriction enzyme plugs

Hey all Today we removed stained and viewed…

Amy Thompson / / Uncategorized

Hey all!

Today we removed, stained and viewed our gel. We saw some very promising results! Although the separation wasn’t great, we saw a large blurred band near the bottom of the gel, near the middle of the low range marker bands present (which unfortunately were quite blurred and difficult to see). This confirmed the presence of DNA in the SpeI treated plug, if not very much, as estimated previously. However, enough DNA was present within the whole plug to show separation, confirming that our plug making procedure and settings were near enough on the right track!

Given the set backs we have been experiencing with the plugs this week and last, this was a real boost to get us excited to start putting our modifications into practise for plug making – increasing cell density/DNA and slightly modifying the PFGE settings – increasing the gel conc. from 1% to 1.4% in order to condense the ladder bands nearer the top, allowing further reference to the Propionbacterium acnes restriction enzyme treated plugs near the middle of the ladder.

We filmed our last videoblog for a week today, as i am away from the lab next week, this will also be my last blog for a week 🙁
Jo will also be away for the next 3 weeks, so we will not be able to put these new modifications into practise just yet! But i am very excited to get started, on what will hopefully be modifications that get us our best results yet for restriction enzyme treated and non restriction enzyme treated plugs on PFGE 🙂

See you all soon!

Hello Today we removed our latest gel stained…

Amy Thompson / / Uncategorized

Hello,

Today we removed our latest gel, stained it and viewed it. Unfortunately we didn’t get very good results – there was alot of blurring on one the low range PFG marker samples, lack of clear band separation on the low range PFG marker samples and no expected band just below the wells for the non restriction enzyme plugs.

We decided that this was most likely due to lack of cell density, and therefore lack of DNA which that could be seen on the gel. We discussed that this could most likely to be fixed by allowing the Propionbacterium acnes samples to grow longer and therefore increase the cell density and DNA, and possibly by centrifuging more of the sample, to reach a higher conc. We also re researched info on cell density within plugs in the manual and journals – we found that the optimum OD was around 0.8-1.0 and we had been working with 0.24. Because of this increase in cell density/conc. we will also need to increase our lysozyme, mutanolysin and proteinase K to compensate.

Mike asked us to run a standard gel, in order to see if there was actually any DNA present at all. We ran a 0.8% gel, for 2 and half hours at 120V/cm with a 1kb ladder. We saw very faint separation, that did confirm that DNA was present, but at very low density/conc. as expected. This also confirmed our modifications which we will put into practise when i come from holiday on Monday 6th August.

After speaking to Mike we decided to attempt to run a new PFGE gel using the whole Propionbacterium acnes restriction treated plug, in one well, in order to use as much DNA as possible, and hopefully see some separation showing multiple bands due to lysis. We ran this 1% gel at 6V/cm, for 15hours with 1-12 sec switch interval ramping, using a whole Propionbacterium acnes restriction treated plug and the low range PFG marker.

Tomorrow we will be viewing this gel and filming our latest videoblog! 🙂