This protocol is taken almost verbatim from the Novagen T7 select systems manual (pg 12).T7 packaging extract is in the T7 select kit in the -80 freezer.
Ligation reactions can be added directly to T7 Packaging Extracts for in vitro packaging. The best T7 packaging results are obtained when the extent of dilution of the extract is minimized. The extracts are supplied in 25 uL single reaction volumes, and the volume of the ligation reaction added to the packaging extract should not exceed 5 uL. Large libraries will require scaling up.
1. Allow the T7Select® Packaging Extract to thaw on ice. The volume of the extract is 25 uL and will package up to 1ug of vector DNA without a loss in efficiency. The extract can be subdivided into several prechilled tubes for testing several DNA samples at once. If performing smaller scale packaging tests, the amount of ligation reaction added must be reduced proportionately. It is only important to use a lot of packaging extract if you are preserving the the the diversity of a library.
2. Add 5 uL ligation reaction per 25 uL extract. Mix gently by stirring with a pipet tip; do not vortex. A vial of T7Select Packaging Control DNA is provided with the system. To test the packaging efficiency independently, add 0.5 ug of the control DNA to 25 uL extract.
3. Incubate the reaction at room temperature (22*°*C) for 2 h.
4. Stop the reaction by adding 270 uL sterile LB or TB medium. If the packaging reaction will be stored for more than 24 h prior to amplification, add 20 uL chloroform and mix gently by inversion. The packaging reaction can be stored for up to one week at 4*°*C without significant losses in titer. For longer term storage, the packaged phage must be amplified. See "phage display- amplification" protocol.