Haynes Lab:Notebook/Investigating Photo-Switchable Synthetic Nucleosomes/2012/12/05

December 5, 2012

11/21/12

Results from last week's ligation

• None of the colonies on any plates grew
• Will retry cloning for each (H2B, LOV) by using the Gibson assembly method

• Repeat PCR of H2B and LOV inserts with new primers
• Note: Primers add a XbaI site upstream and the SpeI site downstream
• Final Gibson assembly products

1. pSB1A3 left end / H2B / LOV +His tag/ pSB1A3 right end
2. pSB1A3 left end / LOV / H2B +His tag/ pSB1A3 right end

• For H2B-LOV construct

1. H2B-GFP plasmid + 1A3/H2B fwd + H2B/LOV rev
2. LOV plasmid + H2B/LOV fwd + LOV+his/1A3 rev

• For LOV-H2B construct

1. H2B-GFP plasmid + 1A3/LOV fwd + LOV/H2B rev
2. LOV plasmid + LOV/H2B fwd + H2B+his/1A3 rev

Performed table reactions twice: once for those used in H2B-LOV construct, once for those used in LOV-H2B construct

PCR program:

• 95°C, 3 min.
• [95°C, 30 sec; 57°C, 30 sec.; 72°C, 30 sec.] x35 cycles
• 72°C, 3 min.
• 4°C ∞

• Clean up PCR products using the Zymo Clean and Concentrator kit
• Be sure to elute using 15 μL dH₂O

• ---Karmella 15:56, 21 November 2012 (EST): Digest, purification, and ligation

Assemblies

1. NEB T4 ligase; H2B - X/S - 410 bp + pSB1A3 - X/S - 2000 bp
2. NEB T4 ligase; LOV - X/S - 461 bp + pSB1A3 - X/S - 2000 bp
3. NEB T4 ligase; (negtaive control) pSB1A3 - X/S - 2000 bp
4. Roche T4 ligase; H2B - X/S - 410 bp + pSB1A3 - X/S - 2000 bp
5. Roche T4 ligase; LOV - X/S - 461 bp + pSB1A3 - X/S - 2000 bp
6. Roche T4 ligase; (negtaive control) pSB1A3 - X/S - 2000 bp

• Digests:
  • In a 30 μL reaction, cut H2B with XbaI and SpeI
  • In a 30 μL reaction, cut LOV with XbaI and SpeI

• Run entire 30 μL on a 1% gel (use the big fat-tooth well comb)
• Cut band out of gel (use UV box)

Results from gel recovery:

1. H2B = 410
2. LOV = 461

• There were two samples made of each PCR reaction. The two from the H2B are shown on the left, and the two from the LOV are shown on the right.

Dephosphorylation (11/23/12)

> Dephosphorylation (Roche)

1. pSB1A3 - X/S = 2000 bp

• Incubate at 37°C/ 10 min.
• Heat inactivate at 75°C/ 2 min.
• [final] = 200 ng/μL / 15 μL = ~13 ng/μL

Ligation

• Use 20 ng of vector for each ligation = 1.5 μL pSB1A3
• Use 3x moles of H2B insert, relative to vector: xμL H2B insert = 3 * 410 bp H2B / 2000 bp pSB1A3 * 20 ng pSB1A3 / 16 ng/μL H2B = at least 0.8 μL H2B
• Use 3x moles of LOV insert, relative to vector: xμL LOV insert = 3 * 461 bp LOV / 2000 bp pSB1A3 * 20 ng pSB1A3 / 25 ng/μL LOV = at least 0.5 μL LOV

Proceed directly to Transformation. See http://openwetware.org/wiki/Haynes:Assembly101