Team:Hawaii/Conjugation Test: Comparing oriT with oriTr

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After the conjugation the colonies will be plated on selection for the donor strain and IPTG and X-Gal for the blue/white screen and on Sm<sub>50</sub>Sp<sub>100</sub> for antibiotic selection.
After the conjugation the colonies will be plated on selection for the donor strain and IPTG and X-Gal for the blue/white screen and on Sm<sub>50</sub>Sp<sub>100</sub> for antibiotic selection.
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# Grow ''E. coli'' in LB with antibiotic selection
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:* Grow ''E. coli'' in LB with antibiotic selection
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:* (mobilizable plasmid)oriTr/J33207 (amp100) in DB3.1
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::* (mobilizable plasmid)oriTr/J33207 (amp100) in DB3.1
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:* (mobilizable plasmid) oriT/J33207 (amp100) in DB3.1
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::* (mobilizable plasmid) oriT/J33207 (amp100) in DB3.1
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:* (self-transmissible plasmid) RP4 (Kan50) in DH5-a
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::* (self-transmissible plasmid) RP4 (Kan50) in DH5-a
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:* (recipient strain)pSMC121 (Sm<sub>50</sub>Sp<sub>100</sub>) in DB3.1
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::* (recipient strain)pSMC121 (Sm<sub>50</sub>Sp<sub>100</sub>) in DB3.1
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# Wash donor and recipient strains with LB to remove the antibiotics.  
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:* Wash donor and recipient strains with LB to remove the antibiotics.  
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# Mix donor and recipient strains (50 ul donor (oriTr/J33207 or oriT/J33207), 50 ul donor (RP4), and 100 ul recipient).
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:* Mix donor and recipient strains (50 ul donor (oriTr/J33207 or oriT/J33207), 50 ul donor (RP4), and 100 ul recipient).
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# Centrifuge briefly and discard supernatant.
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:* Centrifuge briefly and discard supernatant.
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# Re-suspend in 10 ul LB broth.
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:* Re-suspend in 10 ul LB broth.
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# Spot on LB + Agar plate with out selection. Incubate 1 hour at 37&deg;C.
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:* Spot on LB + Agar plate with out selection. Incubate 1 hour at 37&deg;C.
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# Collect spot and make serial dilutions in LB broth.
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:* Collect spot and make serial dilutions in LB broth.
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# Plate dilutions on LB + Agar plates containing Sm<sub>50</sub>Sp<sub>100</sub>, 1mM IPTG and X-GAL.
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:* Plate dilutions on LB + Agar plates containing Sm<sub>50</sub>Sp<sub>100</sub>, 1mM IPTG and X-GAL.
== Results ==
== Results ==
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== Discussion ==
== Discussion ==
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* The experiment was origionally designed to only use Blue/White screening to assess the efficiency of conjugation for both of the plasmids (oriTr/J33207 and oriT/J33207), however to give more certainty to the results, antibiotic selection was also added.
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* The experiment was originally designed to only use Blue/White screening to assess the efficiency of conjugation for both of the plasmids (oriTr/J33207 and oriT/J33207), however to give more certainty to the results, antibiotic selection was also added.
== Reference ==
== Reference ==
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* [[http://openwetware.org/wiki/Conjugation| openwetware.org/wiki/Conjugation]]
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* The protocol was adapted from [[http://openwetware.org/wiki/Conjugation| openwetware.org/wiki/Conjugation]], with additional input from Dr. Callahan.
{{Team:Hawaii/Footer}}
{{Team:Hawaii/Footer}}

Latest revision as of 05:53, 29 October 2008

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Contents

Conjugation Test: Comparing oriT with oriTr

A plasmid can be made mobilizable by adding the origin of transfer of a self-transmissible plasmid. The oriTr is the relaxation region for the R plasmid (i.e. RP4) and is available as a part in the registry. We have constructed another version of this relaxation region: oriT.

We want to compare the efficiencies of these two origins of transfer. To do this, the origins were added to LacZ. After conjugation, the colonies containing the origin of transfer should be identified with blue/white screening and also by antibiotic selection.

Methods

Construction of parts:

  • Extraction of oriTr and J33207 from the BioBrick Registry and synthesis of the oriT derived from RP4.
  • Restriction digest followed by ligation into J33207.

Verification of constructs:

  • PCR of colonies with VF2/VR primers to verify size of insert
  • Sequencing of inserts
  • Blue/White Screen to verify that LacZ works.

Verification/Comparison of oriT

Conjugation

For conjugation, the mobilizable plasmids (oriTr/J33207 and oriT/J33207)in an E. coli strain will be placed together with a strain of E.coli containing a self-transmissible plasmid (RP4) and also a donor strain which contains a non-mobilizable plasmid which is resistant to a different antibiotic.

After the conjugation the colonies will be plated on selection for the donor strain and IPTG and X-Gal for the blue/white screen and on Sm50Sp100 for antibiotic selection.

  • Grow E. coli in LB with antibiotic selection
  • (mobilizable plasmid)oriTr/J33207 (amp100) in DB3.1
  • (mobilizable plasmid) oriT/J33207 (amp100) in DB3.1
  • (self-transmissible plasmid) RP4 (Kan50) in DH5-a
  • (recipient strain)pSMC121 (Sm50Sp100) in DB3.1
  • Wash donor and recipient strains with LB to remove the antibiotics.
  • Mix donor and recipient strains (50 ul donor (oriTr/J33207 or oriT/J33207), 50 ul donor (RP4), and 100 ul recipient).
  • Centrifuge briefly and discard supernatant.
  • Re-suspend in 10 ul LB broth.
  • Spot on LB + Agar plate with out selection. Incubate 1 hour at 37°C.
  • Collect spot and make serial dilutions in LB broth.
  • Plate dilutions on LB + Agar plates containing Sm50Sp100, 1mM IPTG and X-GAL.

Results


Discussion

  • The experiment was originally designed to only use Blue/White screening to assess the efficiency of conjugation for both of the plasmids (oriTr/J33207 and oriT/J33207), however to give more certainty to the results, antibiotic selection was also added.

Reference


[http://manoa.hawaii.edu/ Sponsor_UHM.gif][http://manoa.hawaii.edu/ovcrge/ Sponsor_OVCRGE.gif][http://www.ctahr.hawaii.edu Sponsor_CTAHR.gif]