gDNA Isolation - Mac gigas larvae samples: control larvae 6.7.10 and 5-aza tr larvae 6.7.10

Continued gDNA isolation of the above mentioned larvae samples that was started by Mac yesterday. Amount of larvae in tubes looked disproportionately large, relative to the amount of DNAzol used in the O/N Proteinase K digestion(~500uL) so I added and additional 500uL of DNAzol to each of the two samples and gently pipetted a few times to mix.

Pelleted residual tissue 10mins @ 10,000g @ RT. Transferred supe to new tubes. Precipitated DNA with 0.25mL 100% EtOH. Incubated 3mins @ RT. DNA was pelleted 5mins @ 5000g @ RT. Supe was removed, pellets were washed with 1mL 75% EtOH (x2). Supe was fully removed and the DNAs were resuspended in 800uL 8mM NaOH (made by Amanda Davis 5/20/10).

1M HEPES (provided with DNAzol) was added at a 1:100 dilution to achieve a pH = 8.0. This was based on the DNAzol protocol calculations (For 1mL of 8mM NaOH, use 101uL of 0.1M HEPES = pH 8.0).

Samples were spec’d on NanoDrop 1000 on 20100607. Used a sample with 8mM NaOH and 1M HEPES to match the pH = 8.0 of the samples.


Yields are very good and the 260/280 ratios are pretty good. The 260/230 ratios are very poor and is likely due to the large amount of larvae used in the procedure. Will run samples on a gel to evaluate DNA integrity. **UDPATE: Mac ran these samples on 6/9/10 (see her notebook on that date) and they look perfect.**