Team:Duke/Notebook/July

Miniprep 40 cultures of potential crRNA inserts in pdCas9

• Labeled with three numbers
• Date of transformation - crRNA-GFPx - sample number

700uL of each culture saved to freeze in glycerol if colonies appear successful

• Stored at 4C for the day

Analytical restriction digest of potential crRNA inserts

• All 40 tubes + 2 pdCas9 tubes as control
• 1 uL DNA in 10 uL digest for 2 hrs at 37C
• SacI-HF and NheI-HF in cutsmart

Made and ran 1.5% agarose/TBE gels

• To differentiate between small band differences
• Gel 1:
• 1. 2-log ladder
• 2. pdCas9
• 3-12. pdCas9-crRNA-GFP1 from 7/3 transformation
• 13-22. pdCas9 -crRNA-GFP2 from 7/3 transformation
• 23. pdCas9
• 24. 2-log ladder
• Gel 2:
• 1. 2-log ladder
• 2. pdCas9
• 3-12. pdCas9-crRNA-GFP1 from 7/7 transformation
• 13-22. pdCas9 -crRNA-GFP2 from 7/7 transformation
• 23. pdCas9
• 24. 2-log ladder
• Expected results:
• pdCas9 and successful inserts:
• 3.1, 2.8, and 2.7 kb bands, plus 620 bp insert band
• unsuccessful recircularizations:
• 3.1, 2.8, and 2.7 kb bands, plus 585 bp insert band
• Results:
• Gel 1 appears to only be recircularized
• Gel 2 has some promising inserts:
• GFP1 samples 1,2, and 3 from 7/7 transformation
• GFP2 samples 7,8, and 9 from 7/7 transformation
• Glycerol stocks frozen for these six samples
• Next Steps:
• Run digest with BsaI to confirm that plasmids are not uncut pdCas9
• Sequence to confirm presence of insert (using oligos ordered 7/8/14)

Miniprep 3 new backbones

• pSB6A1-J04450 (3 copies)
• concentrations 437.6, 483.9, and 450.1 ng/uL
• pSB3K3-I20260 (3 copies)
• concentrations 114.6, 120.0, and 97.3 ng/uL
• pSB4K5-J04450 (3 copies)
• concentrations 129.3, 165.9, and 155.1 ng/uL

Prep-scale digest of all 9 backbone tubes

• 50 uL DNA in 60 uL total reaction
• EcoRI-HF/Spe-HF in cutsmart
• 3 hours at 37C

Agarose gel extraction of 3 backbones

• Gel 1, Left: pSB6A1
• Gel 1, Right: pSB3K3
• Gel 2, Left: pSB4K5
• All 3 lanes had 2 bands as expected
• upper band (backbone) in 3K3 had messy trail behind it (not extracted)
• All 180 uL from three tubes combined with 20 uL loading dye in x-large gel well
• top band extracted from all 3 plasmids, split into 2 tubes each, stored at -20C

Streak plate from frozen stock

• pSB1C3-K608012
• In order to switch into pSB6A1

Transformation from iGEM distribution kit plates

• Plate 2-6D: pSB1C3-BBa_R0011
• Engineered Lac promoter (not affected by glucose)
• Plate 3-15O: pSB1C3-BBa_I13500
• Strong RBS-GFP
• Plated on LB+Cm

Gel cleanup of 3 backbones with Zymoclean prep kit

• Some tubes had to be divided into two samples for cleanup
• Final elution was 20 uL each into 2-3 tubes per backbone
• Nanodrops looked unclean: Most had high peak around 220-240 nm
• pSB6A1: 300mg + 120 mg gel = 230.4 ng/uL
• Peak ~220, then hump ~260
• pSB6A1: 270 mg gel = 220 ng/uL
• Peak, then hump as before
• pSB3K3: 320 mg gel = 53.9 ng/uL
• No clear sign of DNA in graph
• pSB3K3: 230 mg gel = 20 ng/uL
• No DNA
• pSB3K3: 130 mg gel = 72 ng/uL
• Possibly DNA, best option but may not be useful
• pSB4K5: 290 mg gel = 43.4 ng/uL
• No clear sign of DNA in graph
• pSB4K5: 320 mg gel = 117.3 ng/uL
• Possibly DNA, best option but may not be useful

Culture 3 colonies of pSB1C3-K608012

• In order to switch into pSB6A1

Analytical Digest of promising crRNA inserts

• XbaI/BsaI digest
• In order to confirm that plasmids are not uncut pdCas9
• Samples 7-1-1,2,3 and 7-2-7,8,9 (6 tubes) plus pdCas9 as control

Agarose gel of digest results:

• 1. pdCas9
• 2-4. pdCas9-crRNA-GFP1, samples 1,2,3
• 5-7. pdCas9-crRNA-GFP2, samples 7,8,9
• Expected:
• 2 bands at 4.2 and 5.1 kb in pdCas9
• 1 band at 9.3 kb in successful plasmids with inserts
• Results:
• pdCas9 appears to be an incomplete digest, showing 2 small and 1 large band
• Lack of any trace of smaller bands in 6 experimental samples indicates successful inserts.

Culture 3 colonies each from pSB1C3-R0011 and pSB1C3-I13500

Culture pSB1C3-I13521 (pTet-RFP)

• For flow
• In aTc and non-aTc

Miniprep 3 copies of pSB1C3-K608012

• concentrations 361, 324, 362 ng/uL

Prep-scale digest of pSB1C3-K608012

• 2 miniprep tubes, 50 uL DNA in 100 uL each
• With EcoRI and SpeI
• 2+ hrs at 37C

Gel extraction and cleanup to isolate K608012

• Cut lower band
• Zymoclean prep kit
• Each of 2 bands divided into two tubes during cleanup
• 1A: 280 mg =
• 1B: 240 mg =
• 2A: 200 mg =
• 2B: 200 mg = 62.5 ng/uL (20 uL)
• Graphs on nanodrop did not look ideal: peak lower than usual

Miniprep pSB1C3-R0011 and pSB1C3-I13500

• 3 copies each
• Concentrations
• pSB1C3-R0011: 181, 229, 194 ng/uL
• pSB1C3-I13500: 321.5, 228, 300.4 ng/uL

Prep scale digests of two tubes from each miniprep

• pSB1C3-R0011 with SpeI/PstI
• no extraction necessary
• pSB1C3-I13521 with XbaI/PstI
• to extract I13521 insert
• 100 uL total reaction per tube
• 2-3 hrs at 37C

Agarose gel of pSB1C3-I13500 XbaI/PstI digests

• Intended for gel extraction
• Expected 2 bands, but only one present
• No extraction performed

Analytical agarose gel of pSB1C3-R0011 SpeI/PstI digests

• Single band appears correct
• see below for gel picture

PCR cleanup of pSB1C3-R0011 SpeI/PstI digests

• concentrations 124.8, 157.3 ng/uL (30 uL each)

Miniprep pdCas9

• concentration 167.4 ng/uL

Prep-scale digest of pSB1C3-R0011

• 1 miniprep with XbaI/PstI
• To extract pSB1C3 backbone

Agarose gel of pSB1C3-R0011 XbaI/PstI digest

• Intended for gel extraction
• Expected 2 bands, but only one present
• No extraction performed

PCR of dCas9-tracrRNA and anti-tracrRNA

• 4 tubes each, with pdCas9 as template in 0, 0.4, 0.7, and 1.0 uL quantities
• oligos dCas9tracr-up and dCas9tracr-dn for dCas9-tracrRNA PCR
• oligos dCas9tracr-up and tracrRNA-dn for anti-tracrRNA PCR
• Q5 polymerase, with 64C annealing and 2 min extension

Agarose gel of PCR (and digest) results:

• Lanes 1-4: dCas9-tracrRNA PCR (0, 0.4, 0.7, 1.0 uL template)
• Lanes 5-8: tracrRNA PCR (0, 0.4, 0.7, 1.0 uL template)
• Lanes 9-10: pSB1C3-R0011 SpeI/PstI digests
• Results:
• dCas9-tracr PCR appears correct, band ~4 kb in 3 lanes
• tracrRNA PCR unclear: strong primer-sized band may be correct, faint bands ~4 kb indicate off-target extension.
• tracrRNA PCR should be done with shorter extension time

PCR cleanup of dCas9-tracrRNA PCR

• Concentration >200 ng/uL

Analytical digest of dCas9

• One tube with BsaI/EcoRI
• One tube with XbaI/EcoRI
• XbaI from tube with exp. 5/14
• One tube with XbaI/EcoRI
• XbaI from tube with exp. 2/15

Agarose gel of digest:

• 1. BsaI/EcoRI: expected 3 bands at 2.7, 2.9, and 3.5 kb
• 2. XbaI (5/14) / EcoRI: expected 3 bands at 5.7, 2.1, 1.4 kb
• 3. XbaI (2/15) / EcoRI: expected 3 bands at 5.7, 2.1, 1.4 kb
• Results: Lanes 1 and 3 look as expected. Lane two has one extra band at 3.5 kb corresponding to partial digestion with XbaI. 5/14 XbaI tube is ineffective and has been thrown out