Tag Archives: Q5 High-Fidelity DNA Polymerase

PCR – Oly RAD-seq Prep Scale PCR

Continuing with the RAD-seq library prep. Following the Meyer Lab 2bRAD protocol.
After determining the minimum number of PCR cycles to run to generate a visible, 166bp band on a gel yesterday, ran a full library “prep scale” PCR.

 

REAGENT SINGLE REACTION (μL) x11
Template 40 NA
ILL-HT1 (1μM) 5 55
ILL-BC# (1μM) 5 NA
NanoPure H2O 5 55
dNTPs (1mM) 20 220
ILL-LIB1 (10μM) 2 22
ILL-LIB2 (10μM) 2 22
5x Q5 Reaction Buffer 20 220
Q5 DNA Polymerase 1 11
TOTAL 100 550

 

Combined the following for PCR reactions:

  • 55μL PCR master mix
  • 40μL ligation mix
  • 5μL of ILL-BC# (1μM) – The barcode number and the respective sample are listed below.

 

SAMPLE BARCODE SEQUENCE
Oly RAD 02  1  CGTGAT
Oly RAD 03  2  ACATCG
Oly RAD 04  3  GCCTAA
Oly RAD 06  4  TGGTCA
Oly RAD 07  5  CACTGT
Oly RAD 08  6  ATTGGC
Oly RAD 14  7  GATCTG
Oly RAD 17  8  TCAAGT
Oly RAD 23  9  CTGATC
Oly RAD 30 10 AAGCTA

 

Cycling was performed on a PTC-200 (MJ Research) with a heated lid:

STEP TEMP (C) TIME (s)
Initial Denaturation
  • 98
  • 30
17 cycles
  • 98
  • 60
  • 72
  • 5
  • 20
  • 10

 

After cycling, added 16μL of 6x loading dye to each sample.

Loaded 10μL of ladder on each of the two gels.

Results:

 

Things looked fine. Excised the bands from each sample indicated by the green arrow. Before and after gel images show regions excised. Will purify the bands and quantify library yields.

Share

PCR – Oly RAD-seq Prep Scale PCR

Continuing with the RAD-seq library prep. Following the Meyer Lab 2bRAD protocol.

After determining the minimum number of PCR cycles to run to generate a visible, 166bp band on a gel yesterday, ran a full library “prep scale” PCR.

 

REAGENT SINGLE REACTION (μL) x11
Template 40 NA
ILL-HT1 (1μM) 5 NA
ILL-BC# (1μM) 5 NA
NanoPure H2O 5 55
dNTPs (10mM) 20 220
ILL-LIB1 (10μM) 2 22
ILL-LIB2 (10μM) 2 22
5x Q5 Reaction Buffer 20 220
Q5 DNA Polymerase 1 11
TOTAL 100 550

 

Combined the following for PCR reactions:

  • 50μL PCR master mix
  • 40μL ligation mix
  • 5μL of ILL-HT1 (1μM)
  • 5μL of ILL-BC# (1μM) – The barcode number and the respective sample are listed below.

NOTE: Samples 02, 03, & 04 did not have 40μL of the ligation reaction left (only 32μL) due to additional usage in the test scale PCR yesterday. Supplemented those three reactions with 8μL of H2O to bring them to 100μL.

 

SAMPLE BARCODE SEQUENCE
Oly RAD 02  1  CGTGAT
Oly RAD 03  2  ACATCG
Oly RAD 04  3  GCCTAA
Oly RAD 06  4  TGGTCA
Oly RAD 07  5  CACTGT
Oly RAD 08  6  ATTGGC
Oly RAD 14  7  GATCTG
Oly RAD 17  8  TCAAGT
Oly RAD 23  9  CTGATC
Oly RAD 30 10 AAGCTA

 

Cycling was performed on a PTC-200 (MJ Research) with a heated lid:

STEP TEMP (C) TIME (s)
Initial Denaturation
  • 98
  • 30
12 cycles
  • 98
  • 60
  • 72
  • 5
  • 20
  • 10

 

After cycling, added 16μL of 6x loading dye to each sample.

Due to limitations in available comb sizes and inability to combine combs to make larger well sizes, only loaded 58μL of samples in each well on this gel. Will load remainder on a second gel and combine after PCR products are purified.

Results:

 

Well, this is lame. There are absolutely no PCR products on this gel. In fact, this just looks like big smears of degraded DNA. I was expecting an amplicon of ~166bp to cut out of the gel. Based off of the test scale PCR from yesterday, everything should have been hunky dory. Not really sure what to think about this…

Share

PCR – Oly RAD-seq Test-scale PCR

Yesterday’s test scale PCR failed to produce any bands in any samples (expected size of ~166bp). This is not particularly surprising, due to the level of degradation in these samples. As such, repeated the test scale PCR, but increased the number of cycles.

Following the Meyer Lab 2bRAD protocol.

I ran PCR reactions on a the same subset of samples as yesterday (Sample #: 4, 7, 14, & 30).

PCR reactions were set up on ice in 0.5mL PCR tubes.

REAGENT SINGLE REACTION (μL) x4.4
Template 8 NA
NanoPure H2O 1 4.4
dNTPs (1mM) 4 17.6
ILL-LIB1 (10μM) 0.4 1.76
ILL-LIB2 (10μM) 0.4 1.76
ILL-HT1 (1μM) 1 4.4
ILL-BC1 (1μM) 1 4.4
5x Q5 Reaction Buffer 4 17.6
Q5 DNA Polymerase 0.2 0.88
TOTAL 20 52.8

 

Combined 12μL of master mix with 8μL of the ligation reaction from yesterday.

Cycling was performed on a PTC-200 (MJ Research) with a heated lid:

STEP TEMP (C) TIME (s)
Initial Denaturation
  • 98
  • 30
42 cycles
  • 98
  • 60
  • 72
  • 5
  • 20
  • 10

We’re following the “1/4 reduced representation” aspect of the protocol. As such, 5μL of each reaction was pulled immediately after the extension (72C – machine was paused) of cycles 27, 32, 37, & 42 in order to determine the ideal number of cycles to use. Also ran the ligation reactions (labelled “ligations” on the gel below) of two samples (samples #: 14 & 30) as a pre-PCR comparison.

These samples were run on a 1x modified TAE 2% agarose gel (w/EtBr).

Results:

 

 

 

 

 

 

 

 

 

 

NOTE: Today’s gel image was taken with a proper gel imager (yesterday’s gel image was captured with my phone). The 27 cycles appears similar to yesterday’s results, even though the bands are not visible on yesterdays’ gel, due to limitations of the phone’s camera sensitivity.

There are a number of bands visible on this gel.

The green arrow on the image identifies what I believe to be the proper size band (~160bp). This band is present in all four cycling groups and at similar intensities across cycling groups.

The two lower molecular weight bands are very likely primer dimers. The Meyer Lab Protocol indicates that primer dimers will likely be present at ~70bp, ~90bp, & ~133bp.

Since we’ve been following along with Katherine Silliman’s 2bRAD progress, here’s an image of her test scale PCR to compare to ours:

Katherine’s test scale PCR. Notice how much more prominent her bands are in all cycle groups, compared to my gel above.

 

Since this is my first foray into RAD-seq QC, I’m not certain whether or not our test scale PCRs indicate any level of success. I will consult with Katherine and Steven about what they think. Since we’re on a timeline, and we’re just testing the viability of this whole process, I suspect Steven will have me proceed and see how things turnout.

Share

PCR – Oly RAD-seq Test-scale PCR

Continuing with the RAD-seq library prep. Following the Meyer Lab 2bRAD protocol.

Prior to generating full-blown libraries, we need to run a “test-scale” PCR to identify the minimum number of cycles needed to produce the intended product size (166bp).

I ran PCR reactions on a subset (Sample #: 4, 7, 14, & 30) of the 10 samples that I performed adaptor ligations on earlier today.

All components were stored on ice.

dNTPs – 1mM working stock was made

  • 10μL dNTPs (10mM)
  • 90μL NanoPure H2O

 

ILL-LIB1 & 2 – 10μM working stocks were made

  • 10μL ILL-LIB1 or -LIB2 (100μM)
  • 90μL NanoPure H2O

 

ILL-HT1 & 2 – 1μM working stocks were made

  • 1μL ILL-HT1 or -HT2 (100μM)
  • 99μL NanoPure H2O

 

ILL-BC1 – 1μM working stock was made

  • 1μL ILL-BC1 (100μM)
  • 99μL NanoPure H2O

 

PCR reactions were set up on ice in 0.5mL PCR tubes.

REAGENT SINGLE REACTION (μL) x4.4
Template 8 NA
NanoPure H2O 1 4.4
dNTPs (1mM) 4 17.6
ILL-LIB1 (10μM) 0.4 1.76
ILL-LIB2 (10μM) 0.4 1.76
ILL-HT1 (1μM) 1 4.4
ILL-BC1 (1μM) 1 4.4
5x Q5 Reaction Buffer 4 17.6
Q5 DNA Polymerase 0.2 0.88
TOTAL 20 52.8

 

Combined 12μL of master mix with 8μL of the ligation reaction from earlier today.

Cycling was performed on a PTC-200 (MJ Research) with a heated lid:

STEP TEMP (C) TIME (s)
Initial Denaturation
  • 98
  • 30
27 cycles
  • 98
  • 60
  • 72
  • 5
  • 20
  • 10

We’re following the “1/4 reduced representation” aspect of the protocol. As such, 5μL of each reaction was pulled immediately after the extension (72C – machine was paused) of cycles 12, 17, 22, & 27 in order to determine the ideal number of cycles to use. Also ran the ligation reactions (labelled “Digests” on the gel below) of two samples (samples #: 4 & 7) as a pre-PCR comparison.

These samples were run on a 1x modified TAE 2% agarose gel (w/EtBr).

 

Results:

 

 

 

 

 

 

 

 

The results aren’t great. No band(s) visible in any samples at even the highest cycle number (27 cycles). Although, if you squint pretty hard, an extremely faint band might be visible in between the 100/200bp markers in the 27 cycles group.

Regardless, the PCRs will need to be repeated with an increased number of cycles. This is not terribly surprising, as the Meyer Lab protocol indicates that degraded samples will likely need a greater number of cycles than what they recommend and that cycle number will have to be determined empirically.

 

Share