Filters for AC48
The AC48 chamber uses 35x41mm filters. Sold in lots of 100.
Polycarbonate track-etch (PCTE) membranes are the primary type of filters used in our chambers and instrument systems. This is a very thin membrane ranging between 6-10µm in nominal thickness. This membrane type offers excellent uniformity in pore size and density, as well as other benefits such as low extractables, low protein binding, and negligible absorption. These characteristics make it ideally suited for use in chemotaxis assays as well as other high purity screening assays.
PVP Treatment –PCTE membranes are available pre-treated with the wetting agent polyvinylpyrrolidone (PVP) which makes the surface hydrophilic. PVP-treated membranes are used when the media solutions cannot wet out the membrane by themselves. This occurs primarily when working with very small pore sizes or high viscosity media solutions. Certain cell types such as neutrophils do not adhere well to PVP treated membranes and tend to drop off after migrating. While this is problematic when quantifying cells on the filter, some researchers using the ChemoTx® sytem or the MB-series 96-well chambers and quantifying in the plate find this to be an advantage. Extra-cellular matrix proteins do not adhere well to PVP treated membranes either. If your assay requires such coating, we recommend using PVP-free membranes.
Filters for the AP48, AC48, AA12 and AA10 are also available in cellulose nitrate. These are much thicker (~150 µm) fibrous filters, sometimes referred to as “torturous path” filters. Rather than counting cells that have migrated through the membrane, as is commonly done with PCTE membrane, these filters are clarified with solvents after a predetermined incubation, and a high-resolution light microscope is used to observe how far into the filter the cells have migrated. This is also known as a “leading edge” study. These filters have a recommended shelf life of one year. They are cut to order, so please allow 2-3 days for processing.
Polycarbonate membranes are available in the following pore sizes and corresponding pore densities:
|Pore size (+0/-20%)||2µm||3µm||5µm||8µm||10µm||12µm||14µm|
(tolerance +/- 15%)
|2 x 104||2 x 104||4 x 103||1 x 103||1 x 103||1 x 103||5 x 102|
Many factors other than cell type enter into the pore size selection process. Please see our page on Experiment Design.