Bio-Rad Bio-Dot® and Bio-Dot SF Microfiltration Apparatus - Manual (Page 7)

Section 3
Bio-Dot SF Assembly
3.1 Assembly
1. Clean and dry the Bio-Dot SF apparatus and gasket prior to assembly.
2. Place the gasket support plate into position in the vacuum manifold. (There is only one way to
slide the plate into the manifold.) Place the sealing gasket on top of the vacuum manifold.
Fig.1. Diagram of proper Bio-Dot SF apparatus assembly.
3. Moisten three sheets of Bio-Dot SF filter paper (catalog number 162–0161) in wetting
solution. Use the same solution that is used to prewet the membrane (step 4). Place the
three sheets onto the membrane support. The filter paper is precut to fit inside the sealing
gasket. Use of Bio-Dot SF filter paper ensures high quality results and eliminates the chance
of cross-well contamination.
4. Always use forceps or wear gloves when handling membranes. Prewet the nitrocellulose or
Zeta-Probe ® membrane by slowly sliding it at a 45° angle into wetting solution. Nitrocellulose
is wetted in 6x sodium, sodium citrate (SSC) for nucleic acid applications, and in Tris-buffered
saline (TBS) for protein binding. Zeta-Probe membrane is wetted in distilled water. See
Sections 9 and 10 for solution preparation. A 10 minute soak is recommended for complete
wetting of the membrane to ensure proper drainage of solutions. Remove the membrane from
the wetting solution. Let the excess liquid drain from the membrane. (Touching the membrane
to a sheet of filter paper is a simple method for removing excess buffer.) Lay the membrane
on the filter paper in the apparatus so it extends over the edges of the filter paper. For the best
slot blot results, use membrane sheets that have been precut to a 9 x 12 cm size (catalog
number 162–0117 for nitrocellulose, 162-0153 for Zeta-Probe membrane). In all cases, the
membrane should not extend beyond the edge of the gasket after the Bio-Dot SF apparatus is
assembled. Remove any air bubbles trapped between the membrane and the filter paper.
Note: PVDF membrane is not recommended.
3
Vacuum manifold
Membrane
Filter paper (3 sheets)
Sealing gasket
Tubing and flow valve
Sample template with attached sealing screws
Gasket support plate