Optional Pre-Treatment to Improve Recovery of Samples from Ultrafiltration Spin Filters Appendix 6.2

Optional Pre-Treatment to Improve Recovery of Samples for Ultrafiltration Spin Filters

Poor sample recover may be experienced with the Omega™ UF membranes and devices because of non-specific adsorption. It is possible to pre-treat these membranes and devices with protein or detergents to reduce the potential for non-specific adsorption of the target analyte. A protocol is outlined below.   

Protocol for Optional Pre-Treatment to Improve Recovery of Samples from Ultrafiltration Spin Filters

1. Add Sufficient volume of one of the following
   1. 1% (w/v) BSA
   2. 1% (w/v) IgG in phosphate buffered saline (PBS)
   3. 5% (w/v) SDS
   4. 5% (v/v) Tween-20
   5. 5% (v/v) Triton^♦-X100 
   6. 5% (w/v) PEG compound in high Purity water to partially fill the UF device.
2. Close the cap and mix by inversion to coat the solution over the internal surfaces of the device.
3. Incubate the solution in the device for at least one hour at room temperature.
4. Discard the above solution by pouring it out of the device, and rinse the device thoroughly with high purity water.
   Tip: Rinsing to remove detergents such as SDS, Tween, and Triton may require more than the above was steps.
5. To ensure that pre-treatment solution is removed from the membrane, add high water to the device and spin at the recommended speed for each device to pass the fluid through the UF membrane. Discard the filtrate.
6. The device can be used immediately or stored for later use. If the device is to be used later, add sterile high purity water (rendered sterile by autoclaving or filtration with a 0.2 µ sterilizing grade filter [see Acrodisc® syringe filters with Supor® PES membrane for sterile filtration (PN 4612)] to the sample reservoir and store at 4º C to retard bacterial growth.
   Tip: Do not allow the membrane to dry out once the device has been pre-treated