RNA Isolation – Geoduck Gonad in Paraffin Histology Blocks

UPDATE 20150528: The RNA isolated in this notebook entry may have been consolidated on 20150528.

Last week’s RNA isolation failed for more than half of the samples I processed. I will re-isolate RNA from the following samples:

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IMPORTANT:

Five 5μm sections were taken from each block. A new blade was used for each block.

Samples were then processed with the PAXgene Tissue RNA Kit in two groups of six.

Isolated RNA according to the PAXgene Tissue RNA Kit protocol with the following alterations:

  • “Max speed” spins were performed at 19,000g.
  • Tissue disruption was performed with the Disruptor Genie @ 45C for 15mins.
  • Shaking incubation step was performed with Disruptor Genie
  • Samples were eluted with 40μL of Buffer TR4, incubated @ 65C for 5mins, immediately placed on ice and quantified on the Roberts Lab NanoDrop1000.

Results:

 

 

 

Well, these results are very consistent with the data from the last isolation performed on these samples. This fact suggests that the problem lies with the tissue samples and not the isolation (since the isolation has been performed two separate times on these same samples and the results have come out virtually identical both times).

All samples with concentrations < 5ng/μL were discarded. The remaining samples were stored @ -80C in Shellfish RNA Box #5:

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  • 38
  • 65
  • 67

Will discuss with Steven, look at Grace’s notebook to review the preservation process for these samples, and review the PAXgene Tissue RNA Kit to see if it will accommodate a greater number of microtome sections to use for isolation.

 

 

5 comments

  1. Hindsight- she did have some issues with proper preservation on some occasions- using wrong sequence of chemicals and/or not getting into building?

    1. I know we discussed this in person, but I’ll post here for posterity.

      As far as I can tell from her notebook, there didn’t seem to be any issues. However, most of the samples that I have been unable to get RNA from are from the very first set that she prepped with the PAXgene Tissue Stabilizer. Could just be coincidence.

      Anyway, as discussed, I’ll try taking some gouges of tissue directly from those blocks and running them through the RNA isolation procedure again.

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