Reagents
- MEM (Sigma catalog #M-0268)
- 2 M CaCl2
- Adenovirus - University of Iowa (VVC-U of Iowa-5 Ad5CMVCre)*
*Note: The University of Iowa facility sends virus at a titer in pfu/ml that is specific for each lot. It is important to minimize freeze/thawing as the titer drops ten-fold each time the virus is frozen. Upon arrival we thaw the virus and aliquot it. Then we thaw an aliquot when we are ready to use it. However, Iowa accounts for one thaw/freeze to aliquot, so no need to adjust the original titer. Ordering information can be obtained from the following people:
University of Iowa
Viral Vector Core
221 EMRB
Iowa City, IA 52242
phone: (319) 335-6726
fax: (319) 335-6895
vectors@uiowa.edu
Ordering:
https://vector-core.medicine.uiowa.edu/collections/ad5
Protocol
Formation of Ad5CMVCre:CaPi co-precipitates:
We typically use 2.5 x 10E7 PFU as our standard dose. You can change the titer by altering the amount of virus used, and adjusting the volume of MEM accordingly in order to give a final volume of 125 uL. When less virus is needed, we normally dilute it in MEM and then use 2.5 uL.
Add 2.5 uL of Ad5CMVCre to 121.9 uL of MEM and mix well. Next add .6 uL of CaCl2 and mix well. Let this mixture sit for ~20 minutes prior to use.
Infection
- Anesthetize the mice with avertin, making sure that the mice are fully anesthetized and have no reaction to pain. I test this by pinching their toe with a pair of forceps. If they are not fully anesthetized they will shake their head scattering the virus.
- Using a protein gel loading tip, take 62.5 uL (half) of the virus mixture and place the pipet tip at the opening of one nostril. It won't fit into the nostril, but that's fine. Slowly expel the virus solution from the tip. Be sure the mouse is indeed inhaling the drop that is forming. If not, stop expelling and wait until it inhales what is there.
- Let the mouse recover for 5-10 minutes. It will cough for a while after inhaling the virus. Wait until its breathing has returned to normal.
- Repeat with the remaining 62.5 uL of virus mixture.
Note: Occasionally, mice don't cope with the avertin very well. It depresses their temperature and breathing rate. If you notice a mouse that is breathing really slowly or shivering, filling a large glove with hot water and placing the mouse on the glove often helps it to recover & survive.
Adeno-Cre or Lenti-Cre Protocol
See:
Dupage M*, Dooley AL*, Jacks T. 2009. Conditional mouse lung tumor models using adenoviral or lentiviral delivery of Cre recombinase. Nature protocols, 4(7): 1064-1072.