Tag: Chloramphenicol

Hello All Unfortunately the re cultured samples hadn’t…

Amy Thompson / / Uncategorized

Hello All,

Unfortunately the re cultured samples hadn’t grown enough on Monday to use, so we left them another day and night until Tuesday. Today, although the growth was minimal we decided to start plug making. We added chloramphenicol to the samples, left them for an hour, and then centrifuged them all down until we had appropriate sized pellets. However, some of the samples did not readily form pellets, and several pellets were much smaller than others or were very dark in colour.

We then combined the pellets with cell suspension buffer, shook them to combine and added agarose. We then pipetted the samples into plug molds and left them to solidify in the fridge. Once solid, we pushed each plug into a separate eppendorf, added appropriate lysozyme, buffer and mutanolysin. However one plug hadn’t soldified enough and was discared. They are now incubating at 37C. At 6, i will remove the lysozyme, buffer and mutanolysin, and add proteinase K and buffer. Incubating them overnight at 50C.

Tomorrow we will be washing the plugs, and incubating them in restriction enzyme, buffer and BSA.

Hey All When we checked the growth of…

Amy Thompson / / Uncategorized

Hey All,

When we checked the growth of the 10 different strain samples of propionibacterium acnes this morning we were happy with most of them, expect a few which were still abit clear. We decided to proceed anyway with plug making, adding chloramphenicol to them for a hour, then centrifuging down 3ml of all samples.
We then centifuged the others further down until all pellets appeared the same size and roughly the same size as the previous most successful plug making. While doing this we melted agarose in a waterbath slowly at 50C.
Once all pellets were appropriate sizes, we added cell suspension buffer, eluted the pellets and added agarose. We kept the agarose, cell suspension buffer and cells at 50C, and pipetted each sample into a mold. Producing 1 plug per sample.
Once solidified, we pushed each plug into a separate universal, added lysozyme, buffer and mutanolysin. This is now incubating at 37C until half 7/half 8pm. After which Mike will remove lysozyme, buffer and mutanolysin and add proteinase K and buffer, incubating it at 50C until tomorrow morning.

Unfortunatly we ran out of lysozyme and proteinase K buffers, so Mike had us make up our own from 1M tris HCL pH8 buffer, sodium dodeyl sulphate (SDS), 0.5M EDTA pH8 and pure water.

Tomorrow we will be washing the plugs and incubating them in SpeI. See you all tomorrow!

Hi all Catching up with last week the…

Deborah / / Uncategorized

Hi all,
Catching up with last week, the plates i innoculated to try and trouble shoot the non growth issues i have been experiencing, showed that there is growth at each stage so at least i can rule out human error, yay! The strain of E.coli i am using (C2110) may be the issue as it is taking 6-7 hours to grow to an OD of 0.35, i would expect the growth to be in the region of 3 hours+. Leaving the plate with no growth on my desk to show mike the next day, miraculously i had fantastic growth overnight. I have already generated data for the plasmids pALA1029, pOG04 NJC, pOG04 DRW, pOG4003 and i am now starting with pOG4 and the Chloramphenicol resistant pNC0412B, fingers crossed all goes well.

Hello Today i began by removing the gel…

Amy Thompson / / Uncategorized

Hello,

Today i began by removing the gel, staining it and viewing it. The gel was much cleaner than before, and the low range PFG marker showed very clear bands, while the restriction enzyme treated plug showed some separation but blurring as before. This confirmed that the problem lies with the plugs, not the settings. Which will hopefully be cleaned up, after DNA conc. is increased in the new plugs.

I began plug making as the Propionbacterium acnes 6919 strain sample had nearly grown enough. Mike suggested i use 2 tubes of 10ml Propionbacterium acnes 6919 strain sample, add chloramphenicol and centrifuge down all 10ml of both samples. This produced a large pellet that i then eluted in cell suspension buffer and combined with agarose. I then pipetted this into 5 plugs molds, and left these to solidify. Once this had happened, i pushed them out into a universal, added lysozyme, buffer and mutanolysin and left to incubate at 37C, for 5 hrs. I then removed this, and added proteinase K and buffer, and incubated overnight at 50C.

Tomorrow i will begin washing the plugs, and treating them with SpeI.

Evening All Didn’t come into the lab till…

Amy Thompson / / Uncategorized

Evening All,

Didn’t come into the lab till 4pm today, in order to allow our Propionibacterium acnes 6919 strain to grow sufficiently. We took 7ml of the Propionibacterium acnes 6919 strain added 14ul of chloramphenicol and incubated for an hour. Then we pipetted 1ml into 2 eppendorfs and spun them down for 5 mins at full speed. Once pellet, we added 250ul of cell suspension buffer into both, shook and then combined. We then added 500ul of melted agarose and pipetted into 5 plug molds. We then put them into the fridge to set.

We have left them in the fridge till tomorrow, when we will treat the plugs with lysozyme, mutanolysin and proteinase K.

See you all tomorrow! 🙂

Good Evening Everyone Busy day today Myself Jo…

Amy Thompson / / Uncategorized

Good Evening Everyone!

Busy day today! Myself, Jo and Mike discussed possible modifications to the plug making method when using Propionibacterium acnes. We decided that we would need to use mutanolysin, which aids in cell lysis, as Propionibacterium acnes can be difficult to break into! We also decided to prolong the incubation time after the addition of mutanolysin and lysozyme from 2 hours to 3 hours at 37°C, in order to give them plenty to time to work on the Propionibacterium acnes.

We then began running through our first attempt at making the plugs! We started by adding chloramphenicol to our Propionibacterium acnes TYGE broth (that Mike inoculated for us). Once that had incubated for an hour we centrifuged it at full speed for 5mins, until we obtained a pellet. We then eluted this pellet in cell suspension buffer. We melted agarose and added these together. We then pipetted this into plug molds, which required a bit of practise! (we made 10 plugs) and left them at 4°C, to solidify. Once set we removed them into a universal tube and added lysozyme, it’s buffer and mutanolysin, it was then incubated at 37°C for 3 hours. We then removed the plugs and rinsed the plugs with pure water. We then added proteinase K and it’s buffer and left it to incubate at 50°C, until tomorrow morning.

We will be washing the plugs A LOT tomorrow! 4 times per plug 1 hour each, with wash buffer! We will then be working through the restriction enzyme digestion of the plugs info, and hopefully get ready to set up our first run with our hand made plugs! 🙂

See you all tomorrow!

Evening All Today myself and Jo came into…

Amy Thompson / / Uncategorized

Evening All! 🙂

Today myself and Jo came into the lab at 9am, and Mike gave us some new stuff to play with! – the newly arrived BioRad plug making kit and restriction enzyme digestion 🙂
We worked through the kit and information provided, made some notes and researched anything we didn’t understand online and through a discussion with Mike. We then produced a new COSHH assessment for our new procedure of making plugs and researched any modifications that journals mentioned when using Propionibacterium acnes specically.

We then made up a stock solution of Chloramphenicol (90 mg/ml), that we will need during plug production. It is a antibiotic, that is bacterial static and stops replication. We will also be using lysozyme, to break down cell membranes, Proteinase K, to break down protein and restriction enzymes, to cut up DNA specifically. Each also has a specific buffer, this is due to enzymes specific nature (pH, Cofactors). We also discussed why it was important to remove remaining EDTA, as it removes cofactors, which are very important to enzyme activity! We also discussed how obtaining the proper cell concentration within the plugs is most likely to be the most difficult part of production. In order to get the most accurate concentration we will be using an OD and CFU/ml against time to produce two sigmoid curves in order to work concentration out.

Excited to start practising these new techniques, so bring on tomorrow morning! 🙂