Matthew Cai:LabNotes/Probe Production and Capture: Difference between revisions

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====First Strand cDNA synthesis====
====First Strand cDNA synthesis====
* Follow NEB E6300S protocol
* Follow NEB E6300S protocol: [https://www.neb.com/protocols/1/01/01/first-strand-cdna-synthesis-e6300]


====Second Strand cDNA synthesis====
====Second Strand cDNA synthesis====
*Follow NEB E6111S protocol
*Follow NEB E6111S protocol: [https://www.neb.com/protocols/1/01/01/second-strand-cdna-synthesis-e6111]


===Padlock Probe Capture===
===Padlock Probe Capture===

Revision as of 22:40, 5 March 2013

Experimental Plan

Oligo Resuspension

  • After receiving the probes, resuspend with H2O to the concentration 20 nM (in case it is lyophilized)

Expansion PCR

Components Volume (ul) Final conc.
20nM CustomArray Inc Oligoes 10.00 1nM
eMIP_CA1_F (100uM) 0.80 400nM
eMIP_CA1_R (100uM) 0.80 400nM
2x Kapa SYBG MM 100.00 1x
H2O 88.40
Total 200.00

Program
95C 30sec -> (95C 5sec -> 52C 60sec-> 72C 30sec) x 5 -> (95C 5sec -> 60C 30sec-> 72C 30sec) x 10-12 -> 72C 2min -> 15C hold

  • Primer info.
    • eMIP_CA1_F: TGCCTAGGACCGGATCAACT (TGCCT overhang), Tm of the short one = 53.06C, the long one = 63.28C
    • eMIP_CA1_R: GAGCTTCGGTTCACGCAATG (GAGCT overhang), Tm of the short one = 54.41C, the long one = 62.95C
  • Note:
    • The first five cycles, Tm of each primer was calculated without 5 nt overhang, then the Tm was increased based on the Tm of the full length primer
    • Monitor number of cycles with real-time thermalcycler to prevent over-amplification. Terminate reactions right before the amplification curve plateaus
  • Purify with Qiaquick column (2 columns) and elute with EB buffer volume 50ul each --> total volume = 100ul
  • Measure DNA conc. with Nanodrop: __
  • Dilute 1st round amplicon to 10nM for use as the template for the future amplification

Production PCR

Components 1 rxn 32x rxn mix
1st round amplicons (10nM) 0.20 6.40
eMIP_CA1_F (100uM) 0.40 12.80
eMIP_CA1_R (100uM) 0.40 12.80
2x Kapa SYBG MM 50.00 1600.00
H2O 49.00 1568.00
Total 100.00 3200.00

Program
95C 30sec -> (95C 5sec -> 60C 30sec-> 72C 20sec) x 13 -> 72C 2min -> 15C hold

  • Monitor cycles to prevent overamplification
  • Check the oligos by running 2ul before amplification in 6% TBU gel and quantify conc. if it corresponds to conc. specified on the tube?
  • Perform EtOH precipitation of the 32 rxn PCR in 4x 15mL tube
    • 800ul amplified amplicon +80ul 3M NaOAc+2.6ul Glycoblue and 2mL 100EtOH
    • incubate at -80C for 30min
    • centrifuge at 3,000 rpm for 30 min at 4C
    • discard supernatant and add 800ul cold 75% EtOH
    • transfer DNA pellet to 1.5 mL tube (using pre-cut 1mL pipette tip)
    • spin at 14,000 rpm for 5 min
    • discard supernatant and air-dry pellet for 5 min in hood
    • resuspend DNA with 150ul H20
    • measure conc. with Nanodrop:__
  • Re-purify amplified-amplicon with Qiaquick column?
    • Pool purified amplicons into one tube and measure DNA conc with Nanodrop:__

Nicking endonuclease digestion

  • Incubate 4ug of amplified amplicon with 10ul of Nt.AlwI (10U/ul) in total volume 200ul at 37C for 1hr (4x reactions?)
  • Heat inactivate enzyme at 80C for 20 min
  • Add 10ul Nb.BsrDI (10U/ul) at 65C for 1 hr
  • Purify with Qiaquick colums, elute with 50ul EB buffer each
  • Measure the conc. of nicked DNA with Nanodrop:__

PAGE size selection

  • Before doing PAGE size selection to purify the 70nt band, Run gel to check if DNA nicking worked well by loading the same amount of DNA before and after incubation with each enzyme at the same amount?
  • After EtOH precipatition and washing, resuspend the probe with 15ul each tube
  • Measure the final concentration:

Sample Prep

  • gDNA: HapMap samples
  • total RNA: human brain reference samples
  • ds cDNA: First and second strand synthesis from total RNA

First Strand cDNA synthesis

  • Follow NEB E6300S protocol: [1]

Second Strand cDNA synthesis

  • Follow NEB E6111S protocol: [2]

Padlock Probe Capture

Design PCR primers

Quantify abundance of initial probes

Design 2 primers