Experimental Protocols

Meeks Laboratory

Preparation of Conjugation Filters                                                                       ELC, 11/2002

The Meeks lab always use Millipore, 0.45 mm, white surfactant free, HATF 82 mm nitrocellulose filters
(cat # HATF08250) for conjugations
1. Always handle the filters only on the edges with forceps. 2. Separate the white filters from the blue filler papers and float the filters in ddw. 3. Turn filters over to make sure that both sides of the filters have been washed. 4. Place the filter in a glass petri plate with Whatman filters in between each conjugation filter. 5. We normally cut a small piece off the Whatman filter so that it's easy to remove and get the conjugation filter. 6. We normally place 10 conjugation filters in each petri plate. 7. Autoclave the prepared filters under slow exhaust. We find that dry exhaust and dry
will shrink the filters and render them unusable.
8. If the filters come out of the autoclave with too much moisture inside the petri plate, then we crack open
the petri plate and place it within the laminar flow hood and let it dry.
9. To use, lift a filter with forceps and place one edge of it down on the agar surface and let the wicking action
carry the rest of the filter down into the surface thereby excluding bubbles between the filter and the surface
of the agar. If a bubble does get trapped, lift the filter gently and replace again. It is important that there be
no bubbles between the filter and the agar surfaces.