— Christine Robbins 2018/05/01 11:05

Often, stock solutions of reagents and drugs cannot be sterilized by being autoclaved. Drugs in particular will degrade at high temperatures. Below are directions for filter sterilizing solutions based on their volume.

Generally, we make stocks of drug solution in small volumes, filter sterilize them and then aliquot them into micro-centrifuge tubes before storing them in the cold. For sterilizing smaller volumes, we us syringes (5mL and 10mL syringes) and attach filters to them.

Location:Syringes and filters can be found on shelf OO

Notes and Warning: We have two types of filters. One that is DMSO safe and one that is not. Please be sure you use the DMSO safe filter if your drug or reagent is dissolved in DMSO.

• After making your solution, grab the appropriate filter and syringe (see not above for selecting your filter)
• Remove the plunder from the syringe and attach the filter
• Holding the syringe and filter over a sterile labeled tube (15mL tube for example), add your media/stock/drug
• ALWAYS KEEP A HAND ON YOUR SYRINGE! IT WILL FALL OVER IF YOU DON'T!!!
• Insert the plunger into the syringe and slowly press down to pass the liquid through the filter
• That's it. Throw the filter and syringe into the tip waste/bio-hazard.

For volumes between 10mL and 50mL, we use a 50mL vacuum filter. This filter works by placing it into a holder and attaching it to the vacuum tube (vacuum filter is located in the fume hood) and adding your liquid. The vacuum will pull it through to the clean, labeled 50mL tube that is attached to the filter.

Location: Cabinet 16

• After making your solution, grab the 50mL filter and label the tube that is attached
• Grab a 50mL tube holder or rack and take the filter and your sample to the hood.
• Attached the white spout that comes with the filter to the hole in the side of the filter
• Attach the tube from the vacuum to the white bit you just attached.
• Remove the cap on the exhaust on the vacuum pump and cover with the 50mL tube next to it, this keeps exhaust from getting in your samples
• Add your sample to the top of the filter and turn the vacuum pump on (the on switch is in the back)
• After your sample is done running, turn off the vacuum and unscrew the 50mL tube that now has your sterile solution in it and place the cap in it.
• That's it. Just clean up your mess and place the exhaust cap back on the vacuum pump.

For volumes that are greater than 50mL, we use a 250mL vacuum filter. This filter gets attached to sterile, labeled bottles before use. If your volume is greater than 250mL, just keep adding to the same filter as it runs though. Remember to swap bottles if the one you are using is getting full.

Location: Cabinet 18

• After making your solution, grab the 250mL filter and label the tube that is attached
• Grab and label the bottle/s that you will need and take them, the filter and your sample to the hood.
• Attach the tube from the vacuum to the white spout on the side of the filter
• Remove the cap on the exhaust on the vacuum pump and cover with the 50mL tube next to it, this keeps exhaust from getting in your samples
• Add your sample to the top of the filter and turn the vacuum pump on (the on switch is in the back)
• After your sample is done running, turn off the vacuum and unscrew the bottle that now has your sterile solution in it and place the cap in it.
• That's it. Just clean up your mess and place the exhaust cap back on the vacuum pump.