Team:Heidelberg/Notebook/Homology Based/September

From 2010.igem.org

Revision as of 12:07, 26 October 2010 by Jude (Talk | contribs)


Contents

September

01/09/2010

  • gel extraction of amplified cap genes
  • 2x DNaseI digestion
    • 1st try: 0.5µl DNaseI, 90s, majority <100bp
    • 2nd try: 0.4µl DNaseI, 75s, majority <100bp
    • gel extraction
  • 1st PCR w/o primers
  • 2nd PCR with SAR (o.n.)


02/09/2010

  • PCR of day before: (1kb Plus)

20100902 thomas virshuf 2ndPCR n.jpg

  • repetition of both PCRs with cap gene fragments of day before by Dirk


  • cap gene DNaseI digestion
3rd try4th try
VDNaseI 0.3µl 0.2µl
tincubation 75s 60s
gel image
1kb Plus
20100902 thomas virshuf DNase 1 n.jpg 20100902 thomas virshuf DNase 2 n.jpg
majority of
fragments
<100bp ~1kb
  • gel extraction
    • miselution into collection tube
  • nucleotide removal
    • c ≈ 37ng/µl in 32µl each ⇒ enough for 3 PCRs each


03/09/2010

  • both PCRs with cap fragments of day before
    • bands at ~100bp → probably primer binding to small fragments, 1st PCR not working
    • no bands at ~2kb → no success


06/09/2010

  • cap gene DNaseI digestion
5th try6th try
VDNaseI 0.25µl 0.25µl
tincubation 75s 75s
gel image
1kb Plus
20100906 thomas DNaseI 5 n.jpg 20100906 thomas virshuf DNase 6 n.jpg
majority of
fragments
~400bp ~300bp
  • no gel extraction
  • repetition of whole DNA shuffling by Dirk: success
    • assumption: problem at the production of the cap genes → restart of very first PCR the day after


07/09/2010

  • amplification of cap genes (1,2,5,6,8,9) out of pBluescript vectors
    • 4 aliquots each, only 2 for AAV9
  • gel extraction


08/09/2010

  • cap gene DNaseI digestion
1 (Thomas)4 (Philipp)2 (Thomas)5 (Philipp)
VDNaseI0.3µl0.27µl0.35µl0.45µl
tincubation75s75s75s75s
gel image
1kb Plus
20100908 thomas virshuf DNase 1 Phil 4.jpg20100908 thomas virshuf DNase 2 Phil 5.jpg
majority of
fragments
~250bpwidespread~500bp<100bp
  • gel extraction
  • 1st and 2nd PCR
    • again failed: 1 left, 4 right
    • expectation: clear bands at ~2.2kb

20100908 thomas virshuf 1 4 2ndPCR.jpg


09/09/2010

  • 2nd PCR of samples 2 and 5:

20100909 Thomas virshuf 2 5 2ndPCR.jpg

  • desired product at 2.2kb visible
  • repetition of 3 more PCR samples for preparation


10/09/2010

  • PCR of day before:

20100910 Thomas virshuf 2 2ndPCR prep.jpg

  • gel extraction of highest clear band from all lanes


⇑ top

10/09/2010

cap Gene Shuffling (starting over again)

cap PCR

PCR to amplify the cap genes from the stock.

  • 5 ul cap plasmid (40 ng/ul stock)
  • 1 ul M13For
  • 1 ul M13Rev
  • 10 ul 5x Hifi buffer
  • 1 ul Hifi (Quiagen)
  • 32 ul H2O

Cycles (Program name: "shuffle 1st"):

  • 95 °C for 5 min
  • 94 °C for 15 sec |
  • 57°C for 30 sec | 40x
  • 68 °C for 3 min |
  • 72 °C for 10 min
  • 4 °C hold

Gel Extraction:

10092010 AAV125 capPCR.jpg 350px

DNAse Digest

cap gene mix (4ug DNA total):

B1/B2 (09/15)  !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

AAV m [ng] c [ng/ul] V [ul]

1 350 121.0 2.9
2 700 115.0 6.1
5 1200 93.0 12.9
6 350 105.0 3.3
8 700 172.0 4.1
9 700 186.0 3.8

H2O 20.5

DNAse Digest:

  • 4 ug DNA cap gene mix
  • 6 ul 10x buffer
  • 0.3 ul DNAse I (invitrogen)

Directly after adding of DNAse:

  • Flick tube three times
  • Start timer 75 sec
  • Quick run on the centrifuge (5 sec)
  • Incubate on Thermoblock (Eppendorf)
  • Add 6 ul 25 mM, vortex briefly
  • Inactivate at 75 °C for at least 10 min

Gel Extraction:

10092010 capMIX1 DNAse.jpg

Re-Assembly PCR

500 ng input from purified DNAse digest 10 ul Phusion HF Buffer 1 ul dNTPs 1.5 ul DMSO 0.5 ul Phusion Polymerase ad 50 ul H2O

Amplification PCR

2 ul Re-Assembly PCR product 1 ul SAFor 1 ul SARev 0.5 ul MgSO4 10 ul 5x Hifi Buffer 33.5 ul H2O

Cycles 2-step PCR protocol (Program name: "shuffle phil", left PCR):

95 °C for 5 min 94 °C for 15 sec | 68°C for 3 min | 40x 72 °C for 10 min 4 °C hold


⇑ top

10/09/2010

  • PCR of day before:

10092011 capMIX1 product.jpg 10092011 capMIX2 DNAse.jpg

ToDo

ShufflingSchedule

20/09/2010

  • PCR-shuffled capsid genes from AAV serotypes 1,2,5,6,8 and 9 were digested with PacI and AscI overnight at 37ͦC according to the following protocol:

- 15 µg capsid genes. - 7 µL AscI - 7 µL PacI - 20 µL 10X NEB buffer 4 - 2 µL 100X - Up to 200 µL nuclease-free water

  • The vector pTR-UF3 was digested with pTR-UF3 using AscI and PacI for 5 hours according to the following protocol:

- 10 µg vector - 2 µL AscI - 2 µL PacI - 5 µL 10X BSA - 5 µL 10X buffer 4 - Up to 50 µL nuclease-free water

21/09/2010

  • The digested capsid fragments and the vector were loaded on a 1% agarose gel and ran for 50 minutes. The ~2.2 KB (capsid genes) and ~5 KB (vector) fragments were then purified from the gel.
  • A ligation reaction was carried out according to the following protocol:

- ~3.556 µg insert (Capsid genes) - ~2.667 µg vector - 6 µL T4 DNA ligase - 8 µL T4 DNA ligase buffer - Up to 80 µL nuclease-free water - Incubate at 16 ͦC overnight

22/09/2010

  • The ligation product from the day before was used to transform electrocompetent cells (Invitrogen), according to the following:

- 600 µL of electrocompetent bacteria were mixed with 62.5 µL DNA from the ligation reaction (about 125 ng per 20 µL bacteria), 20 µL of the mixture were placed in the electoporation cuvette

- Electroporation conditions:

- Recovery of bacteria was done by adding 1 mL LB media to each 20 µL of bacteria that were electroporated. The bacteria were collected in a 200 mL flask and incubated at 37ͦC with shaking at 225 rpm for 1 hour.

The bacteria were then used to inoculate 15 cm petri dishes with ampicillin resistance media. 500 µL were spread on each plate, and 50 plates in total were inoculated. The plates were incubated at 37 ͦC overnight.

23/09/2010

  • The plates from the previous day were collected, and 50 colonies were picked and used to inoculate miniprep cultures.
  • The colonies from the 50 plates were pooled together and cultured in 700 mL LB for 3 hours, after which a Megaprep (Invitrogen) was done (according to manufacturer's recommendations) to extract the plasmids that contain the shuffled capsid genes and create a library of those shuffled capsids that would be used for the selection of the best capsids, and thus best AAVs.
  • A left-over from the transormation from previous day was stored in the fridge and used to inoculate three more 15 cm plates, since the other 50 plates were not suitable for counting the colonies (very crowded!) to estimate the size of the library.

24/09/2010

  • 5 flasks (?) of HEK cells were transfected with a total of 75 µg of the library DNA and AAV helper plasmid (1:1) for AAV production, using HBSS. However, the transfection was not successful.
  • minipreps of the 50 picked colonies were done, and 10 clones were sent for sequencing. Test digestion with AscI, PacI indicated that the clones picked were positive for the insert (capsid genes).
  • Counting of the colonies on the plates from the previous day showed a library size of (...)?

50 more colonies were picked from one of the plates and used to inoculate mini-prep cultures.


25/09/2010

  • Analysis of the sequencing results indicated good shuffling of the capsids of two samples, while the 8 others had mainly the sequence of the capsid of AAV5.
  • 50 mini-preps of the colonies picked on the previous day were initiated.

27/09/2010

  • The 50 samples from the mini-preps from the previous day were test-digested with AscI and PacI, and additionally with NcoI to identify whether AAV5 is present more than the other serotypes. The test digestion with NcoI revealed an AAV5 contamination, so most samples were positive for the AAV5 pattern when digested with NcoI. Sequencing of 10 more samples confirmed this finding.

28/09/2010

  • The source of the contamination with AAV5 was identified. The second PCR for the shuffled capsids was repeated.

29/09/2010

  • The 2.2 KB band corresponding to cap genes was purified from the gel that was run for the PCR from the previous day. Digestion of the purified cap genes and the pTR-UF3 was done overnight using AscI and PacI according to the same protocol from the previous time.

30/09/2010

  • Ligation of the cap genes into the pTR-UF3 vector was carried out accoring to the same protocol from the previous time, the ligation time was 6 hours instead of overnight ligation.
  • Transformation of Invitrogen electrocompetent cells was done like the previous time and according to manufacturer's recommendations.


August
MTWTFSS
1
2345678
9101112131415
16171819202122
23242526272829
3031
September
MTWTFSS
12345
6789101112
13141516171819
20212223242526
27282930
-
October
MTWTFSS
010203
04050607080910
11121314151617
18192021222324
25262728293031
-