音時雨 ~Regentropfen~

✽ Real-time Lab Trace [part. 7: Apr. 14-19]

Day 25. 2008/04/14
Today’s all results were strange. The plasmids extracted by Kit not so pure, because there were two bands stay at near positions where my plasmid should be. Although I took about four hours to digest, of the five samples I only got one MAY BE what I want.
So that tomorrow I will have to extract again, by hand and Kit respectively.
Day 26. 2008/04/15
I extracted the plasmids by Kit, but the photo was still not very perfect (080415-PLASMID.jpg). Maybe my gel had something incorrect.
XhoI digestion was not good too. When I checked my primers in the evening, I got very surprised. My sense primer not concludes XhoI site, but EcoRI and NcoI!
Now, the problem got solved.
Day 27. 2008/04/16
Digestion 1 (I got the enzymes a wrong quality, which should be 0.5, but I added 1, so the concentration was wrong):
B1 & R1: XhoI 1; BamHI 1; 10×K Buffer 1; ddH2O 3; plasmid 5;
B2 & R2: XhoI 1; NcoI 1; 10×K Buffer 1; 10×BSA 1; ddH2O 2; plasmid 5;
R3 (only a little test for another two sites on pMD-18): EcoRI 0.5; HindIII 0.5; 10×M Buffer 1; ddH2O 3; plasmid 5;
But the cut bands were so faint that I couldn’t see it well without Photoshop editing (080416-digestion1.jpg). I guessed it was because of that I added more plasmids.
So…
Digestion 2
B1 & R1: XhoI 0.5; BamHI 0.5; 10×K Buffer 1; ddH2O 6; plasmid 2;
B2 & R2: XhoI 0.5; NcoI 0.5; 10×K Buffer 1; 10×BSA 1; ddH2O 5; plasmid 2;
R3 (only a little test for another two sites on pMD-18): EcoRI 0.5; HindIII 0.5; 10×M Buffer 1; dd H2O 5; plasmid 2;
This time the bands were little lighter (I only detected two of them), but still faint. So I left the other tubes to digest overnight.
Waiting for tomorrow’s electrophoresis.
Day 28. 2008/04/17
The overnight digestion wasn’t more ideal than 1-2 hours reaction. I even couldn’t find any bands on the gel!
Sure, that’s only a test, what I should to do was to extract enough plasmids, and this time I also used the Kit.
But…
Oh! My goodness! I forgot to change the spin column onto another EP tube, so I had to precipitate plasmid DNA by ethanol that afternoon. Good luck, the result was not bad.
Then, from my tutor I got 10μl of E. coli which including the expression plasmid pET30a, and also 1.5μl of pure plasmid pET30a and pGEX6-1. I transferred the 10μl bacteria into liquid LB with Kan.
Day 29. 2008/04/18
I did a 100μl digestion for later gel extraction, (080418-digestion2-100ul.jpg).
The pET30a bacteria didn’t grow! I added some LB into the original EP tube, swung for 1 hour, then transferred into antibiotic free LB.
Day 30. 2008/04/19
The antibiotic free LB got some bacteria, but LB-Kan didn’t turn cloudy, so I had to transfer the pure plasmids into E. coli.
Maybe later I will try to make competent cells, so I needed to preserve some plasmid free cells. I added 35μl competent cell into the pGEX6-1 and pET30a vectors respectively, and the last 30μl of cell I transferred into antibiotic free liquid LB.