Tag Archives: cDNA

qPCR – Water Filter cDNA for RLO Viability Assessment

Ran qPCRs on the cDNA I made earlier today to determine if there’s any detectable RNA in any of these water filter samples.

Master mix calcs (Google Sheet): 20161208- qPCR WSN1

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_2016-12-08 09-14-38_CC009827_cDNA_WSN1.pdf
qPCR File (CFX96): Sam_2016-12-08 09-14-38_CC009827_cDNA_WSN1.pcrd

Original qPCR File (CFX96): Sam_2016-12-08 09-14-38_CC009827.pcrd

Standard curve looks good.

The following cDNA samples had detectable amplification:

  • T1A
  • T1B
  • T3A
  • T3B

I believe that the labelling scheme represents T1 = Day 1 in water, T3 = Day 3 in water.

These results suggest that the RLO is viable outside of the abalone host for at least three days, but not >= 7 days, although the values are below the theoretical qPCR limit of detection. These results will likely be used to help Lisa with experimental design for a more involved assessment of RLO viability in the water column.

I’ve added the data to Lisa’s spreadsheet (Google Sheet: RLO viability) in the “Expt 1″ worksheet.

Update after talking to Lisa: The water was shipped from a California abalone farm O/N, so T0 = 24hr water. The Control water samples were sea water from our basement facility, not from California.

The fact that there is no amplification at T0 is a bit surprising and possibly suggests that RLO viability outside of the host is on the magnitude of hours, not days…

 

 

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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.

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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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Reverse Transcription – Subset of Jake’s O.lurida DNased RNA

Currently don’t have sufficient reagents to perform reverse transcription on the entire set of DNased RNA (control and 1hr.heat-shocked O.lurida ctenidia samples). To enable Jake to start testing out some of his primers while we wait for reagents to come in, Steven suggested I generate some cDNA for him to use.

Used the following DNased RNA:

  • HC1
  • NC1
  • SC1
  • HT1 1
  • NT1 1
  • ST1 1

Reverse Transcription Calcs: 20150522_Jake_Oly_cDNA_Calcs

Briefly:

  • Reactions run in 0.5mL snap cap tubes
  • 250ng of DNased RNA used in each reaction
  • Combined DNased RNA with oligo dT primers and water; incubated 70C 5mins; immediately placed on ice
  • Added 6.75μL of buffer/dNTP/enzyme master mix to each sample; incubated 42C for 1hr; 95C for 3mins

Samples will be given to Jake and stored @ -20C.

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qPCR – Withering Syndrome cDNA Tests

The qPCR on withering syndrome water filter cDNA that I ran earlier today didn’t amplify in any samples, and I neglected to run a positive control primer set on the cDNA to verify that the reverse transcription was successful.

Ran a qPCR using universal 16s primers, EUB A/B.

Additionally, I ran qPCRs using the WSN1 primers on cDNA from black abalone digestive gland (Dg), in case the RNA from the water filters doesn’t actually contain any viable rickettsia-like organisms (RLO).

cDNA templates used:

  • 08:3-7 (from 20090422)
  • 08:3-14 (from 20090422)
  • Day 0-1 (from 20150317)
  • Day 3-1 (from 20150317)
  • Day 7-1 (from 20150317)
  • Day 11-1 (from 20150317)

Note: The black abalone cDNA was made using oligo dT primers, so it’s unlikely to contain many prokaryotic targets.

Withering syndrome positive control:

EUB positive control:

Master mix calcs are here: 20150319 – qPCR WS cDNA test

All samples were run in duplicate. See qPCR Report (see Results) for plate layout, cycling params, etc.

Results:
qPCR Report (PDF): Sam_2015-03-19 14-29-09_CC009827.pdf
qPCR Data File (CFX96): Sam_2015-03-19 14-29-09_CC009827.pcrd

WSN1 primers:

There is amplification in the abalone cDNA. This tells us that the withering syndrome qPCR assay will work for detection of cDNA.

No amplification from the water filter cDNA. It suggests that there’s no detectable cDNA in the withering syndrome water filter cDNA .

EUB primers:

There is no amplification in any of the cDNA samples. However, one abalone cDNA produced amplification with the EUB primers, but with an extremely late Cq (Cq = 39) and in only one of the two replicates.

These data suggest that the RNA isolation was unsuccessful. Either the RNA quality is too degraded (we know that the OD 260/280 values are very poor) or there just isn’t sufficient RNA present in the samples to allow us to detect it.

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qPCR – cDNA from 20120208

Performed qPCR on all 12 samples. Used the following primers, provided by Elene, to detect V.tubiashii expression:

  • rseA_F/R
  • VtpA_F/R
  • VtpR_F/R

Used RE22 DNA (provided by Elene) as a positive control. Master mix calcs are the same as yesterday’s qPCR, but using the primers mentioned above. Plate layout, cycling params, etc. can be found in the qPCR Report (see Results). All samples were run in duplicate.

Results:

qPCR Data File (CFX96)

qPCR Report (PDF)

Positive control worked in all primer sets. All no template controls were clean for all primer sets.

Only one sample (#411) produced any amplification. Amplification was detected in the vtpA primer set (mean Cq = 38.06). However, there was also amplification detected in one of the two replicates for sample #411 in the rseA primer set (Cq = 39.09).

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qPCR – cDNA from earlier today

Performed qPCR on all 12 samples. Used Cg_EF1aF/R2 (SR IDs: 1410 & 1412) for one set of qPCRs and Vtub_16s_F/R (SR IDs: 455 & 456) for the other set of qPCRs. Used pooled C.gigas cDNA (from 20110311) and RE22 DNA (provided by Elene) as positive controls for C.gigas and V.tubiashii, respectively. C.gigas gDNA (7ng of BB16 from 20110201) was used as a negative control for EF1a. Master mix calcs are here. Plate layout, cycling params, etc can be found in the qPCR Report (see Results). All samples were run in duplicate.

Results:

qPCR Data File (CFX96)

qPCR Report (PDF)

C.gigas EF1a – Positive control amplified. Negative control and no template control were all clean (i.e. no amplification detected). The majority of samples had amplification, however two samples had no amplification at all (samples 132 & 136).

V.tubiashii 16s – Positive control amplified. No template controls exhibited amplification in both replicates. All samples exhibited amplifcation, however nearly all of the melt curves have multiple peaks present, suggesting that more than one target is being amplified. I suspect this is due to residual gDNA, but this fails to explain the amplification in the no template controls which also exhibited dual peaks in the melt curves.

Spoke with Steven and he suggested to skip troubleshooting the V. tubiashii 16s for now and proceed with trying to qPCR some additional V.tubiashii genes. Will talk with Elene to see if/which additional genes she has primers for.

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PCR – Full-length PGS1 cDNA

Still have insufficient quantities of DNA for sequencing. Master mix calcs and cycling params are here. Additionally, used some of the purified PCR product as template in one of the reactions, just for comparison purposes. cDNA template was pooled cDNA from 20110311 from various C.gigas tissues. Also, increased the amount of template 4-fold in an attempt to obtain higher yields of PCR products for sequencing.

Results:

Lane 1: Hyperladder I (Bioline)

Lane 2: PCR 1 (cDNA template)

Lane 3: PCR 2 (cDNA template)

Lane 4: PCR 3 (PCR template)

Lane 5: Neg. Control

Bands were excised and will be purified using Ultra-free DA columns (Millipore). Also, it’s very clear that using the purified PCR product as template produced a much greater yield, although there appear to be some spurious, high-molecular weight banding/smearing.

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PCR – Full-length PGS1 cDNA

Need more PCR product for sequencing. Repeated reaction from 20110825.

Results:

Lane 1 – Hypperladder I (Bioline)

Lane 2 – PCR 1 & 2

Lane 3 – PCR 3 & 4

Lane 4 – PCR 5 & 6

Lane 5 – Neg. Control

Bands from lanes 2 – 4 were excised and purified with Ultra-free DA columns (Millipore) and spec’d. Concentration was extremely low (3.5ng/uL) and too dilute for sequencing. Will EtOH precipitate.

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PCR – Full-length PGS2 cDNA

Repeated PCR from 20110825 to attempt to amplify the full-length cDNA for PGS2 (COX2), however this time using a more robust polymerase (Amplitaq Gold) in hopes of getting results. Additionally, tried 3 different Mg2+ concentrations (1.5mM, 2.0mM, and 3.0mM). Master mix calcs and cycling params are here. cDNA was pooled cDNA made 20110311 from various tissues. PGS2 primers = 1376, 1375.

PGS2 expected size = ~2500bp

Results:

Loading order doesn’t matter, as there are no bands. Ladder is Hyperladder I (Bioline). Will continue current sequence analysis and potentially design a new set of primers…

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