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TUDelft/18 August 2008
From 2008.igem.org
18th August
DNA extraction test
Today a gel was run with DNA soaked from the spots. To test the soaking-protocol, various steps of the protocol were performed on the DNA. Either just soaking at Tr or 20' at 42 C, and one also spinned. To test DNA concentrations before running the gel, to predict whether something should be visible, nanodrops were performed.
| Sample | ng/ul | A260/A280 |
|---|---|---|
| H2O | 0.42 | -0.24 |
| TE | 1.12 | -1.19 |
| TE + Punch, 23 C | 42.24 | 0.67 |
| TE + Punch, 42 C | 36.51 | 0.62 |
| TE + Punch, 42 C + Spinned | 44.15 | 0.61 |
This would imply that heating might not have a beneficial effect on DNA extracting, although it has to be taken into account that spot sizes are far from identical. All the 260/280 values imply low purity of the DNA, as it approaches more closely the value of protein instead of DNA. The blanc was not TE but H2O, which might have a negative effect on the ratio.
The gel run of the extracted DNA did not show any bands at all, possibly due to low quantity as nanodropped DNA was usually half of the remaining fluid. Another cause might be low quality DNA.
Live stabs
Today the live stabs of a couple of biobricks and plasmids also arrived, we immediately put in o/n LB cultures of 5 ml, everything on Ampicillin.
