Tag Archives: DNased RNA

Reverse Transcription – Ronit’s C.gigas DNased ctenidia RNA

Proceeded with reverse transcription of Ronit’s DNased ctenidia RNA (from 20181016).

Reverse transcription was performed using 100ng of each sample with M-MMLV Reverse Transcriptase from Promega.

Briefly, 100ng of DNased RNA was combined with oligo dT primers and brought up to a final volume of 15uL. Tubes were incubated for 5mins at 70oC in a PTC-200 thermal cycler (MJ Research), using a heated lid. Samples were immediately placed on ice.

A master mix of buffer, dNTPs, water, and M-MMLV reverse transcriptase was made, 10uL of the master mix was added to each sample, and mixed via finger flicking. Samples were incubated for 1hr at 42oC in a PTC-200 thermal cycler (MJ Research), using a heated lid, followed by a 5min incubation at 65oC.

Samples were stored on ice for use later this afternoon by Ronit.

Samples will be stored in Ronit’s -20oC box.

Reverse transcription calcs (Google Sheet):

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qPCR – Ronit’s DNAsed C.gigas Ploidy/Dessication RNA with elongation factor primers

After I figured out the appropriate DNA and primers to use to detect gDNA in Crassostrea gigas samples, I checked Ronit’s DNased ctenidia RNA (from 20181016) for residual gDNA.

Elongation factor primers:

  • EF1_qPCR_5′ (SRID 309)
  • EF1_qPCR_3′ (SRID 310)

BB16 from 20090519 was used as a positive control.

Samples were run on Roberts Lab CFX Connect (BioRad). All samples were run in duplicate. See qPCR Report (Results section) for plate layout, cycling params, etc.

qPCR master mix calcs (Google Sheet):


Results

qPCR Report (PDF):

qPCR File (PCRD):

qPCR Data (CSV):

In the plots below, green is the positive control, blue are the samples, and red is the no template control (NTC).

Everything looks great! Nice, clean, gDNA-free RNA! Will proceed with reverse transcription.


Amplification Plots


Melt Curves

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qPCR – Ronit’s DNAsed C.gigas Ploidy/Dessication RNA with 18s primers

After DNasing Ronit’s RNA earlier today, I needed to check for any residual gDNA.

Identified some old, old C.gigas 18s primers that should amplify gDNA:

  • gigas18s_fw (SRID 157)
  • gigas18s_rv (SRID 156)

Used some old C.gigas gDNA (BB15 from 20090519) as a positive control.

Samples were run on Roberts Lab CFX Connect (BioRad). All samples were run in duplicate. See qPCR Report (Results section) for plate layout, cycling params, etc.

qPCR master mix calcs (Google Sheet):


Results

qPCR Report (PDF):

qPCR File (PCRD):

qPCR Data (CSV):

Well, this primer set and/or the gDNA is not good. In the plots below, the positive control gNDA is in green, samples in blue, and no template controls (NTC) are in red.

Poor performance is most easily noticed when looking at the melt curves. They have multiple peaks, suggesting non-specific amplification, even in the positive control.

Additionally, although less evident from just looking at the plots, is the replicates are highly inconsistent. Although it’s possible that might be due to poor technique, it’s very unlikely.

Will have to identify different primers and/or positive control DNA.


Amplification Plots


Melt Curves

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Samples Received – Pinto Abalone DNased RNA from UC-Irvine

Received DNased pinto abalone RNA from Alyssa Braciszewski at UC-Irvine. These are subset of the samples I sent her back in February.

Here’s the samples list provided by Alyssa (Google Sheet): shipment to UW of RNA samples.xlsx

The samples need to be confirmed to be free if residual RLO gDNA via qPCR. If they are clean, then will proceed to making cDNA, using provided reagents.

Reagents were stored in door of -20C in FSH 240.

Samples were stored in the provided box in the “new” -80C in FSH 235.

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DNA Quantification – RLO viability DNased RNA

I previously DNased RNA I isolated from water filters that were part of the RLO viability experiment that Lisa and the Capstone students are conducting. I checked for residual gDNA carryover via qPCR and all of the samples that were intended for dosing the abalone came up positive. It’s likely due to such a high quantity of algae that was co-filtered with the potential RLOs, leading to over-saturation of the RNAzol with DNA, resulting in the gDNA carryover.

In turn, I think the DNase treatment was insufficient for the quantity of carryover DNA.

I am planning on re-DNasing those samples, but want to quantify any residual DNA present to make sure that the samples aren’t still too concentrated for the DNase.

Samples were quantified using the Robert Lab Qubit 3.0 and the Qubit dsHS reagents (high sensitivity), using 1uL of sample.

Results:

Residual DNA is still present, but at levels that are well below the maximum that the DNase treatment (10ug) can handle. I will redo the DNase treatment on these samples. Spreadsheet is linked, and embedded below, with sample concentrations.

Spreadsheet (Google Sheet): 20170424_filter_rna_dna_quant

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qPCR – Capstone RLO Viability DNased RNA

Need to verify that the DNased RNA I made previously does not have any detectable gDNA present.

Ran the withering syndrome qPCR assay on the DNased RNA.

Standard curve was p18RK7 from 20161128.

All samples were run in duplicate. As such, the number of samples required to qPCR runs.

Master mix calcs are here (Google Sheet): 20170406_qPCR_WSN1_capstone

Plate layout, cycling params, etc. can be found in the qPCR Report (see Results).

Baseline threshold was manually set to 580, as previously determined by Lisa.

Results:

qPCR Report (PDF): Sam_2017-04-06 10-01-23_CC009827.pdf
qPCR Data File (CFX96): Sam_2017-04-06 10-01-23_CC009827.pcrd

qPCR Report (PDF): Sam_2017-04-06 11-36-53_CC009827_capstone_RLO_viability_WSN1.pdf
qPCR Data File (CFX96): Sam_2017-04-06 11-36-53_CC009827_capstone_RLO_viability_WSN1.pcrd

Well, some samples came up positive for residual DNA. The samples that came up positive are all three dilutions of the RLO used for initial infection of the abalone.

This makes things interesting to deal with. Seeing that no other samples have detectable DNA suggests that those samples are fine to move forward with for reverse transcription. However, it’s unlikely that the DNase treatment only worked on a subset of a samples, since it was distributed via a master mix.

Regardless, there isn’t any additional RNA to work with. So, I’ll put the samples that came up positive through a second round of DNase treatment. Addtionally, I may dilute them slightly to avoid complications from accumulation of too much DNase buffer, due to leftover buffer from the first round…


Amplification Plots from Sam_2017-04-06 10-01-23_CC009827.pcrd

Green = p18RK7 standards
Blue = samples
Red = No template control

 

Standard Curve from Sam_2017-04-06 10-01-23_CC009827.pcrd

 

 

Amplification Plots from Sam_2017-04-06 11-36-53_CC009827_capstone_RLO_viability_WSN1.pcrd

 

 

Standard Curve from Sam_2017-04-06 11-36-53_CC009827_capstone_RLO_viability_WSN1.pcrd

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DNase Treatment – Abalone Water Filters for RLO Viability

The RNA I isolated earlier today was subjected to DNase treatment using the Turbo DNA-free Kit (Invitrogen), following the manufacturer’s standard protocol.

After DNase inactivation treatment, the RNA was transferred (recovered ~19uL from each samples)  to a clear, low-profile PCR plate.

The plate layout is here (Google Sheet): 20170309_RLO_viability_DNased_RNA_plate_layout

The samples will be subjected to qPCR to assess the presence/absence of residual gDNA. The plate of DNased RNA was stored @ -80C in the original box that the water filters were stored in.

An overview of the experiment and the various treatments are viewable in the “Viability Trial 2″ tab of Lisa’s spreadsheet (Google Sheet): RLO Viability & ID50

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Reverse Transcription – Water Filter DNased RNA (from 20161207)

Performed reverse transcription on the DNased RNA samples that I verified were free of detectable RLO DNA (20161207).

Combined 17μL DNased RNA + 0.5μL random primers (Promega; Cat: C1181) in 0.2mL PCR tubes.

NOTE: The 17μL was virtually all of the sample volume recovered from DNasing. As such, the DNased RNA will not be quantified.

Incubated DNased RNA and primer mix in PTC-200 thermal cycler (MJ Research) at 70C for 5mins w/heated lid, then immediately placed on ice.

Created master mix of following components:

REAGENT SINGLE REACTION VOL (μL) NUMBER REACTIONS TOTAL VOL (μL)
5x MMLV RT BUFFER 5 14 70
10mM dNTPS (Promega) 1.25 14 17.5
MMLV RT (Promega) 0.5 14 7

Added 6.75 of master mix to each and mixed by pipetting.

Incubated PTC-200 thermal cycler (MJ Research) @ 37C for 1hr (no heated lid), followed by 95C for 3mins (heated lid). Samples were transferred to 0.5mL snap cap tubes and labelled with “cDNA” and the corresponding sample name. Samples will be stored in my -20C box.

UPDATE 20170830 Lisa has moved these samples to a -20C box dedicated to RLO Viability cDNA.

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qPCR – DNased RNA from Abalone Water Filters (from earlier today)

Prior to creating cDNA, need to verify that the DNased RNA from earlier today doesn’t contain any detectable RLO DNA.

Master mix calcs (Google Sheet): 20161128 – qPCR Water Filter DNased RNA

All samples were run in duplicate. Plate layout, cycling params, etc. are in the qPCR Report (see Results below).

Standard curve was the p18RK7 curve made on 20161128.

Baseline threshold was manually set to 580, as previously determined by Lisa for this assay.

Results:
qPCR Report (PDF): Sam_2016-12-07 09-10-07_CC009827.pdf
qPCR File (CFX96):Sam_2016-12-07 09-10-07_CC009827.pcrd

Standard curve looks good.

No samples amplified. This suggests that there is no detectable DNA in any of the DNased RNA samples. Will proceed with making cDNA.

 

 

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Reverse Transcription – O.lurida DNased RNA 1hr post-mechanical stress

Performed reverse transcription on the Olympia oyster DNased RNA from the 1hr post-mechanical stress samples from Jake’s project. To accommodate the large numbers of anticipated genes to be targeted in subsequent qPCRs, I prepared 100μL reactions (normally, 25μL reactions are prepared) using 250ng of each DNased RNA. A 1:10 dilution of the oligo dT primers (Promega) was prepared to improve pipetting accuracy. All incubations were performed in a thermal cycler without using a heated lid.

DNased RNA was combined with NanoPure H2O and oligo dT primers in 24 wells of a PCR plate, heated @ 70C for 10mins and immediately placed on ice. After 5mins, the plate was spun 2000g @ RT for 2mins and returned to ice.

25.25μL of a master mix containing 5x M-MLV Buffer (Promega), dNTPs (10mM each; Promega), and M-MLV Reverse Transcriptase (50U/rxn; Promega) was distributed to each well and mixed via pipetting. The plate was heated @ 42C for 1hr, 95C for 3mins. The plate was spun 2000g @ RT for 2mins and then stored @ -20C.

Plate layout and all calculations can be found here (Google Sheet): 20150806_Jake_oly_mech_stress_cDNA_calcs

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