Tag Archives: DNA

Ethanol Precipitation – Full-length PGS1 cDNA (from 20110921)

Performed an EtOH on gel-purified PCR products from 20110921. Briefly, added 0.1 vols of 3M sodium acetate (pH=5.2; 43uL), mixed and then added 2.5 vols of 100% EtOH (1182.5uL). Mixed, split into two tubes (due to high volume not fitting in a single tube) and incubated @ -80C O/N. Pelleted DNA 16,000g, 20mins, 4C. Discarded supe. Washed pellet w/ 1mL 70% EtOH. Pelleted DNA 16,000g, 15mins, 4C. Discarded supe. Resuspended both pellets in a TOTAL of 25uL Qiagen Buffer EB (10mM Tris-HCl) and spec’d.

Results:

Now have sufficient DNA for sequencing.

What’s next?

Generate PCR product using primers that anneal OUTSIDE of each of the qPCR primers and then sequence those bands to ensure that the qPCR primers are actually annealing to two different isoforms.

Ethanol Precipitation – Purified PGS1 PCR from yesterday

Added 0.1 vols of 3M sodium acetate (pH = 5.2; 38uL) and 2 vols of 100% EtOH (836uL). Incubated 30mins @ -20C. Pelleted DNA 16,000g, 15mins, 4C. Removed supe. Washed pellet w/1mL 70% EtOH. Pelleted DNA 16,000g, 15mins, 4C. Removed supe. Air-dried pellet. Resuspended in 50uL of Qiagen EB Buffer and spec’d.

Results:

Insufficient quantity of DNA for sequencing. Will re-run PCR, but will use some of this purified DNA as template to see if that helps increase yields.

Restriction Digestions – HpaII and MspI on Mac’s C.gigas gDNA Samples: Round 1

Set up restriction digests for subsequent analysis by methylation specific PCR (MSP). This will be the first of two rounds of digestion with the same enzyme on each sample. Samples and master mixes are here. Samples were incubated 3hr. @ 37C. All samples were heat inactivated at 80C for 30mins and then stored @ -20C.

MeDIP – SB/WB Fragmented gDNA EtOH precipitation (continued from 20100702)

Finished EtOH precipitation of MeDIP gDNA. Samples were pelleted 16,000g, 4C, 30mins. Supe was discarded. Washed with 1mL 70% EtOH, pelleted 16,000g, 4C, 15mins. Supe discarded. MeDIP DNA was resuspended in 100uL of TE (pH = 8.5). Wash samples, containing unmethylated DNA, were resuspended/combined in a total of 100uL TE (pH = 8.5). Samples were spec’d:

Results:

R37: MeDIP DNA = 1.393ug recovery. This is ~13% of the input total gDNA (11.25ug) and is ~28% of the total DNA recovered in the procedure (4.935ug). Unmethylated DNA = 3.542ug total recovery. This is ~31% of the input total gDNA (11.25ug) and is ~72% of the total DNA recovered in the procedure (4.935ug). Total DNA recovery = ~44%.

R51: MeDIP DNA = 1.256ug recovery. This is ~14% of the input total gDNA (8.75ug) and is ~23% of the total DNA recovered in the procedure (5.462ug). Unmethylated DNA = 4.206ug total recovery. This is ~48% of the input total gDNA (8.75ug) and is ~77% of the total DNA recovered in the procedure (5.462ug). Total DNA recovery = ~62%.

There definitely seemed to be a high degree of salt carryover from the procedure, despite the phenol:chloroform treatment and EtOH precipitation. As such, I believe this is the reason that the 260/230 ratios are so out of whack. Possibly explains why the 260/280 ratios for the MeDIP DNA are so high, too?

These results demonstrate what we can expect to recover from this procedure, as well as how much DNA gets lost during processing. MeDIP DNA and unmethylated DNA were stored @ -20C.

DNA Precipitation – C.pugetti DNA for JGI submission (continued from yesterday)

Sample was removed from -20C and spun @ 4C, 16,000 x g for 30mins. Supe removed, pellet washed with 1mL 70% EtOH and spun @ 4C, 16,000 x g for 15mins. Supe removed, tube spun briefly and remainder of EtOH removed. Pellet was resuspended in 100uL of 1x TE and spec’d. Sample will be run on a gel according to JGI instructions.

Results:

The only thing that could be worse about this gel would be no sample DNA. However, what we see here (the giants smear in middle of the gel is our sample) is completely degraded OR sheared gDNA. That means this gDNA is absolutely useless now. Will start growing more cultures for another massive gDNA isolation.