Transgenic Core Facility:

DNA Preparation Protocols

(Click here to download an MS Word file of these protocols)

 

DNA Preparation Protocols

 DNA purification for transgene microinjection

  1. Recombinant plasmid should be purified by CsCl gradient or Qiagen Maxi-prep. The insert must then be separated from the vector by restriction digestion, since vector sequences can significantly alter the expression of transgenes.
  2. Separate the insert from the vector on an agarose gel run in Tris/Acetate/EDTA(Not Tris/Borate/EDTA) buffer. Use 5 mg/ml Ethidium bromide for gel staining. Visualize the DNA with long wavelength UV light to avoid damaging the ethidium bromide-intercalated DNA.
  3. Excise the gel slice containing the gene fragment of interest and electroelute the DNA, or else process though Qiaex gel extraction kit (Qiagen, Inc.) according to manufacturer's instructions.
  4. Ethanol precipitate the DNA. For ethanol precipitation of sample, add 1/10 volume of 3 M NaAcetate, mix, then add 2-2.5 volumes of 100% ethanol. Incubate at -20º C overnight, then spin 5 minutes in a microcentrifuge to pellet the DNA. Resuspend in Elutip buffer (Schleicher and Schuell)
  5. Pass the DNA through an DEAE Elutip-D mini-column.(Schleicher and Schuell catalog # 27370).
  6. Ethanol-precipitate the DNA as above. Wash the pellet several times with 70% ethanol and dry the pellet under vacuum. The washing and drying steps are very important, as residual salt and ethanol are lethal to the developing embryo. Resuspend in sterile MiTE (10mM Tris/0.1mM EDTA, pH 7.4 prepared with Sigma embryo tested water (Cat # W-1503) or Milli-Q quality water.
  7. Estimate the DNA concentration. Run a small sample of the prepared fragment on a agarose gel alongside uncut plasmid and a set of known standards such as lambda-HindIII markers A photograph of this gel must accompany all requests for microinjection. Adjust the DNA concentration to around 4ng/ul in MiTE and make sure there is at least 150 ul of volume to be submitted to the Transgenic Core Facility.

Be sure to label the tube with the concentration and volume and your name for the DNA construct before submitting the DNA to the Transgenic Core Lab. The DNA should be brought to Room C1732 (Macromolecular Core Facility) no later than noon of the Friday before your first injection is scheduled. The DNA should be put in Room C1732 (Macromolecular Core Facility) the 2nd freezer on the left, just past the 2nd door on the left of and should be properly labeled for easy identification.

NOTE - All PAPERWORK required should be placed in the tray inside the door of Room C1735 (Mass Spec/Proteomics Core facility), NOT left in C1732


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Last revised: January 24, 2008



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