Tag Archives: Chionoecetes bairdi

RNA Isolation – Lyophilized Tanner Crab Hemolymph in RNAlater

Due to difficulties getting RNA from hemolymph samples stored in RNAlater, Grace is testing out lyophilizing samples before extraction. Who knows what impact this will have on RNA, but it’s worth a shot!

Isolated RNA from three crab hemolymph samples preserved in RNAlater (Test 1, Test 2, Test 3) that had been lyophilized overnight last week.

Samples were provided by Grace.

I believe the primary purpose for this particular test was to verify that the freeze dryer was a feasible tool, since Grace experienced a minor mishap when she attempted the lyohpilization initially.

Lyophilization was successful, without any mess.

TEST 3 LYOPHILIZATION


Isolated RNA using TriReagent, according to manufacturer’s protocol:

Added 1mL TriReagent to each tube, vortexed to mix/dissolve solute, incubated 5mins at RT, added 200uL of chloroform, vortexed 15s to mix, incubated at RT for 5mins, centrifuged 15mins, 12,000g, 4oC, transferred aqueous phase to new tube, added 500uL isopropanol to aqueous phase, mixed, incubated at RT for 10mins, centrifuged 8mins, 12,000g, at RT, discarded supernatant, added 1mL 75% ethanol, centrifuged 5mins, 12,000g at RT, discarded supernatant and resuspended in 10uL of 0.1% DEPC-treated H2O.

Quantified RNA using Roberts Lab Qubit 3.0 with the Qubit RNA high sensitivity kit. Used 5uL of each sample.


RESULTS

Qubit (Google Sheet):

Only one sample (Test 3) had detectable levels of RNA (20.4ng/uL).

So, this little test demonstrates that RNA can be isolated from lyophilized samples and extracted with TriReagent. However, I have not evaluated RNA integrity on the Bioanalyzer. I think Grace has some additional samples she wanted to test this method on, so I think we’ll wait until there are more samples before we use the Bioanalyzer.

Will give sample to Grace for -80oC storage.

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RNA Isolation & Quantificaiton – Tanner Crab Hemolymph

Isolated RNA from 40 Tanner crab hemolymph samples selected by Grace with the RNeasy Plus Micro Kit (Qiagen) according to the manufacturer’s protocol, with the following modifications:

  • Added mercaptoethanol (2-ME) to Buffer RLT Plus.

  • All spins were at 21,130g

  • Did not add RNA carrier

  • Used QIAshredder columns to aid in homogenization and removal of insoluble material

  • Eluted with 14uL

RNA was quantified using the Qubit RNA HS (high sensitivity) Assay and run on the Roberts Lab Qubit 3.0.

Used 1uL of sample for quantification.

RNA was returned to the -80C box from where original samples had been stored (Rack 2, Row 3, Column 4).


RESULTS

Qubit quantification (Google Sheet):

Overall, the results aren’t great. Only 15 samples (out of 40) had detectable amounts of RNA. Yields from those 15 samples ranged from 40ng – 300ng, with most landing between 50 – 100ng.

Will pass info along to Grace. Will likely meet with her and Steven to discuss plan on how to move forward.

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Bioanalyzer – Tanner Crab RNA Isolated with RNeasy Plus Mini Kit

Ran the four Tanner crab RNA samples that I isolated yesterday on the Seeb Lab Bioanalyzer 2100 (Agilent) using the RNA Pico 6000 Kit.

Samples were run following kit protocol:

  • Chip priming station in Position C with syringe clip at top position

  • RNA denatured at 70C for 2mins and stored on ice.

  • RNA ladder aliquot was from 20160826 by Hollie Putnam.


RESULTS

Bioanalyzer data file (XAD):

ELECTROPHEROGRAMS:


GEL REPRESENATATIONS


These results look great to me. Clear, defined peaks/bands, representing ribosomal RNA.

Oddly, one sample (crab_506) appears to be shifted, relative to the other three, despite exhibiting the same peak/banding pattern. Not sure what would cause something like this; contaminants?

Regardless, we finally have clean RNA and have a usable Bioanalyzer profile to use for reference for crab RNA.

NOTE: The lanes marked with red on the gel representation image indicate that a ribosomal integrity number (RIN) could not be calculated. This is to be expected! The RIN is based on the expectation of two rRNA bands. The anomaly is sample crab_451 – a RIN was actually determined for that sample!

Will likely move forward with additional RNA isolations using the RNeasy Plus Kit (Qiagen).

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RNA Cleanup – Tanner Crab RNA

In a continued attempt to figure out what we can do about the tanner crab RNA, Steven tasked me with using an RNeasy Kit to cleanup some existing RNA.

Here’re the samples grace provided:


All of the RNA had some sort of undissolved/insoluble material present. Here’s an example (this is the worts of the bunch – others did not have such large/dense pellets):


Samples were cleaned up using the [RNeasy Plus Mini Kit (Qiagen)]. Added 350uL of Buffer RLT Plus (no beta-mercaptoethanol added) to each sample, vortexed, and then processed according to the manufacturer’s protocol (skipped gDNA Eliminator spin column step).

Samples were eluted with 30uL of nuclease-free water.

Samples were quantified using the Roberts Lab Qubit 3.0 with the RNA High Sensitivity asssay (Invitrogen). Used 5uL of sample for measurements.

Samples were also assessed with the Roberts Lab NandoDrop1000.

Samples were recovered from the pedestal after measurement.

RNA was given to Grace for storage at -80C.


RESULTS

Qubit measurements (Google Sheet):
20180731_qubit_RNA_crab_cleanup


NanoDrop Table:


All concentrations were too low for detection via NanoDrop.

Qubit quantification indicate yields ranging from ~25ng to ~192.5ng.

Will share info with Grace and let her compare these numbers to her original concentrations to see if there’s any differences.

Regardless, based on my earlier RNA isolation today, these samples should now be much cleaner and we should be able to trust the Qubit quantifications.

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RNA Isolation – Tanner Crab Hemolymph Using RNeasy Plus Mini Kit

Tanner crab RNA has proved a bit troublesome. As such, Steven asked me to try isolating some RNA using the RNeasy Plus Mini Kit (Qiagen) to see how things would turn out.

Grace provided me with the following samples:


Crab hemolymph had been collected (100uL?) and preserved with 1mL (?) of RNAlater. Grace pelleted the samples, removed the supernatant, and stored the pelleted material at -80C. Here’s what that looked like:


RNA was isolated according to the manufacturer’s protocol – following guideline for samples with < 1 x 106 cells.

One interesting thing that happened is a precipitate formed after adding the initial buffer to the sample:

A solid precipitate formed in each of the tubes that could not be dispersed – it actually looked like a small piece of paper was now present in each tube.

Samples were spun and the supernatant was utilized (this was the normal progression of the protocol, regardless of this precipitate forming).

Samples were eluted with 30uL of nuclease-free water.

Samples were quantified using the Roberts Lab Qubit 3.0 with the RNA High Sensitivity asssay (Invitrogen). Used 5uL of sample for measurements.

Samples were also assessed with the Roberts Lab NandoDrop1000. Samples were recovered from the pedestal after measurement.

RNA was given to Grace for storage at -80C.


RESULTS

Qubit measurements (Google Sheet):
20180731_qubit_RNA_crab_isos


NanoDrop Spec Curves:


NanoDrop Table:


Overall, the isolation looks pretty good. The purity looks good (NanoDrop 260/280 ratios) and the absorbance peak at 260nm is exactly where we would want/expect it to be.

The yields (according to the Qubit) are OK. They range from ~37ng – 350ng.

The important part is that this method produced clean RNA, which means the quantification is believable. I think Grace’s earlier RNA isolations using RNAzol RT had too much contamination carried over, leading to incorrect quantification measurements.

Going forward, I think we need to use some sort of isolation kit, however, we will be testing out good, old TriReagent as well.

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RNA Isolation & Quantification – Tanner crab hemolymph

We received three Tanner crab (Chionoecetes bairdi)hemolymph samples from Pam Jensen (NOAA) yesterday. From her email to Steven:

Hi Steven,
I am sending:
tube #1 crab 3859/3656: 300 ul blood + 1300 ul RNAlater​

tube #2 crab 3665/3873: 300 ul blood + 1300 ul RNAlater
​tube #3 crab 3665/3873: 200 ul blood + 1400 ul RNAlater​

The tubes hold max of 1600 ul. Will know on Sun or Mon if either crab is infected w Hematodinium.

Tracking info to follow.
Pam

Samples were stored at 4C O/N.

Here’s what the samples looked like before processing:

The samples are extremely cloudy. I’m not sure if this is expected.

Processed samples using RNAzol RT (MRC) according to the manufacturer’s protocol for Total RNA Isolation.

Pelleted samples at 5000g for 5 mins and the samples looked like this:

Decided to pellet samples for an additional 10mins. The pellet was more compact. Transferred supernatant to clean tube, since it seemed to contain “debris” (maybe cells?). Processed pellet with RNAzol RT. Brief rundown of procedure (all steps at room temp):

  1. Transferred supe to clean tube.
  2. Added 1mL RNAzol RT to pellet and mixed by repeated pipetting (solution was cloudy and slightly viscous).
  3. Added 400uL of 0.1% DEPC-treated H2O and mixed vigorously by hand.
  4. Incubated for 10mins.
  5. Centrifuged 12,000g for 15mins.

    Samples looked like this:

    This is not normal. Usually the supernatant is the clear portion, while the blue layer is below that.
  6. Transferred 750uL of the clear portion to clean 1.7mL tube.

  7. Added equal volume of isopropanol, mixed by inversion. Appeared to be a very high amount of genomic DNA precipitation visible in the tube.
  8. Incubated for 10mins.
  9. Centrifuged 12,000g, 15mins.

    Samples looked like this:

    It appears that the nucleotides (the white interphase) are suspended on a “cushion” of higher density solution, instead of pelleted at the bottom of the tube.
  10. Removed/discarded higher density solution, leaving the white layer on the bottom of the tube.

  11. Centrifuged 12,000g, 15mins.
  12. Discarded supe.
  13. Washed pellet with 75% ethanol.
  14. Centrifuged 8,000g, 3mins.
  15. Repeated Steps 12, 13, & 14, 1x.
  16. Discarded ethanol.
  17. Resuspended RNA in 50uL 0.1% DEPC-treated H2O. Pellets did not solubilize on their own. I dispersed the pellets by repeated pipetting (P200). Remaining insoluble material was pelleted (12,000g, 30s) and supernatant was transferred to a new 1.6mL tube.

RNA was quantified using the Qubit 3.0 and the Qubit HS RNA Assay. Used 5uL of each sample.

Results:

20171107_qubit_tanner_crab_hemo (Google Sheet)

Sample ID Conc. (ng/uL) Total Yield (ng)
3859/3656 0.44 22
3665/3873 1.66 83
3665/3873 2.04 102

Interestingly, both samples from the same crab had similar/decent yields.

Samples were labeled and stored at -80C in Shellfish RNA Box #6

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