Filter sterilize

Use filter sterilization if heat sterilization by autoclave is not possible.

Essential when making stock solutions for antibiotics and other heat sensitive compounds.

For small volumes:

• Suck up the to be sterilized liquid into a syringe
• Attach the appropriate disk filter
• Prepare a sterile container/tube/bottle to collect the liquid in
• Press the liquid through
  • Wear eye protection as the filter might shoot of if too much pressure is applied (also: don't apply too much pressure)
  • The filter might get clogged when large volumes or very 'dirty' liquid is filtered. Again, be careful not too apply too much pressure when this happens. Better to change to a new filter and only then continue filtering.
• Aliquot when needed

For large volumes:

• Take a sterile bottle
• Attach a cup filter on the top of the bottle
• Connect the filter to the vacuum tap on the bench next to the waterbath
• Fill the cup with the to be filtered liquid
• Open the tap. The liquid will now be sucked through the filter. You can top up the cup during this time.
• Wait for the liquid to be completely passed through the filter and close the bottle with a sterile cap.