Tag Archives: RNAse A

DNA Isolation – Oly gDNA for BS-seq

Need DNA to prep our own libraries for bisulfite-treated high-throughput sequencing (BS-seq).

Isolated gDNA from the following tissue samples stored in RNAlater (tissue was not weighed) using DNAzol:


The sample coding breaks down as follows (see the project wiki for a full explanation):


2 = Oysters outplanted in Fidalgo Bay

NF = Broodstock originated in Fidalgo Bay

# = Sample number


1 = Oysters outplanted in Oyster Bay

NF = Broodstock originated in Fidalgo Bay

# = Sample number


DNA was isolated in the following manner:

  • Homogenized tissues in 500μL of DNAzol (Molecular Research Center; MRC).
  • Added additional 500μL of DNAzol.
  • Added 10μL of RNase A (10mg/mL, ThermoFisher); incubated 10mins @ RT.
  • Added 300μL of chloroform and mixed moderately fast by hand.
  • Incubated 5mins @ RT.
  • Centrifuged 12,000g, 10mins, RT.
  • Transferred aqueous phase to clean tube.
  • Added 500μL of 100% EtOH and mixed by inversion.
  • Pelleted DNA 5,000g, 5mins @ RT.
  • Performed 3 washes w/70% EtOH.
  • Dried pellet 3mins.
  • Resuspended in 100μL of Buffer EB (Qiagen).
  • Centrifuged 12,000g, 10mins, RT to pellet insoluble material.
  • Transferred supe to clean tube.

The samples were quantified using the Qubit dsDNA BR reagents (Invitrogen) according to the manufacturer’s protocol and used 1μL of sample for measurement.


Qubit data (Google Sheet): 20151216_Oly_gDNA_qubit_quants

2NF1 76.4
2NF2 175
2NF3 690
2NF4 11.7
2NF5 142
2NF6 244
2NF7 25
2NF8 456
1NF11 182
1NF12 432
1NF13 155
1NF14 21
1NF15 244
1NF16 112
1NF17 25.2
1NF18 278


Will run samples on gel tomorrow to evaluate gDNA integrity.

DNA Isolation – Geoduck & Olympia Oyster

Amazingly, we need more gDNA for the two genome sequencing projects (geoduck and Olympia oyster). Used geoduck “foot 1″ sample from Box 1 of the foot samples collected by Brent & Steven on 20150811. Used Olympia oyster adductor muscle from Box 1 of adductor muscle sample collected by Brent & Steven on 20150812.

Also need to evaluate DNA quality of initial broodstock samples from Jake’s Olympia oyster reciprocal transplant experiment. Used mantle samples stored in EtOH collected by Hannah (see her notebook entries on July 25 & Sept 5, 2013)

Tissue weights:

  • Geoduck foot: 108.5mg (gone)
  • Olympia oyster adductor: 258.7mg (gone)
  • Oly NF1A: 7.1mg (gone)
  • Oly SN49A: 20.8mg


Samples were isolated using DNAzol (Molecular Research Center) according to the manufacturer’s protocol, with the following adjustments:


  • Tissues homogenized in 750μL of DNAzol with disposable mortar/pestle tubes using 10 pestle strokes
  • After homogenization, topped off tubes to 960μL with DNAzol, added 40μL RNAse A (100mg/mL) and incubated @ RT for 15mins.
  • Performed optional centrifugation step (10,000g, 10mins @ RT)
  • Initial pellet wash was performed using a 70%/30% DNAzol/EtOH
  • Pellets were resuspended Buffer EB (Qiagen)
  • Insoluble material was pelleted (12,000g, 10mins @ RT) and supe transferred to new tubes


Genome sequencing resuspension volumes: 50μL

Oly reciprocoal resuspension volumes: 25μL

Spec’d on Roberts Lab NanoDrop1000.



Genome Sequencing Samples

The 260/280 ratios look fine. The 260/230 ratios look poor, as is usually the case after DNAzol isolations.


Geoduck: 7.6μg

Oly: 16.5μg

The geoduck yield is insufficient to make up the quantity of gDNA still needed by BGI for sequencing. Will have to isolate more gDNA on Monday.


Reciprocal Transplant Samples

The 260/280 ratios look fine. The 260/230 ratios look poor, as is usually the case after DNAzol isolations.


NF1A: 7,1μg

SN49A: 1.375μg

The yields are surprisingly good! Next up is to evaluate the gDNA quality on a gel to see if the samples from this experiment will be usable.