Instructions on the handling of syringe filters
Not every filter membrane is suitable for every task. We have compiled a brief overview in order to give you information on special features when using different pore sizes.
1. Properties of filters in relation to the pore size:
| Cleaning operation | Pore size to be used (µm) |
|---|---|
| Sterile filtration | 0,2 |
| Thorough cleaning | 0,45 |
| Clear filtration (freedom from particles) | 1-2 |
| Preliminary filtration | 5,0 |
The following table gives you an overview of the approximate volumes of the liquids to be filtered which can be passed through a membrane of a defined diameter. Greater deviations from the specified average value may occur, depending on the particle charging of the liquid concerned.
2. Relationship of filterable sample quantities to the filter diameter:
| Filter diameter (mm) | Sample quantity (ml) |
|---|---|
| 4 | <1 |
| 13 | 1-10 |
| 25 | 10-100 |
| 30 | >100 (or fast filtration) |
The specified values are approximate values
In the case of solutions which are difficult to filter, high pressures may be necessary under certain circumstances, in order to force the relevant liquid through a filter. The following table has been compiled in order to estimate the pressures required and determine the corresponding filters. (In conjunction with the Technical specifications of syringe filters).
3. Manually generated maximum pressure in relation to syringe volume:
| Syringe volume (ml) | Pressure (bar / psi) |
|---|---|
| 1 | 10 / 150 |
| 3 | 7 / 100 |
| 5 | 5 / 75 |
| 10 | 3,5 / 50 |
| 20 | 2 / 30 |
The specified values may vary depending on the person in question. The bar/psi conversion has been rounded
If you require further information, please refer to:
Stefan Kölzer, Sales engineer, Life Science / Filtration Technology
stefan_koelzer@dia-nielsen.de
