How to clean glassware

Small flasks (50 ml)

The 50 ml flasks are used in quantity in many experiments and need to be cleaned and sterilized on a regular basis.

Summary: autoclave (wet) → rinse/wash → autoclave (dry) → sterile cabinet

Detailed procedure:

1. Autoclave trays of flasks that were used for growing microbial cultures (including lids) on liquid cycle for 1 hour.
2. After autoclaving, remove lids and rinse thoroughly with DI water. The lids can then be placed in secondary container (usually a large autoclave tray) and allowed to air dry.
3. Dump the sterilized contents of the flasks down the drain, rinse each flask a few times with DI water, and placed rinsed flasks in dishpan. If there is any noticeable debris in the flasks, let them soak full of water and/or scrub them with a brush. Do not use soap, which can inhibit the growth of microbes!
4. Put flasks into the dishwasher (WEL: 2nd floor) and wash using cycle 7. This takes about 45 minutes.
5. After washing, place flasks into a stainless steel tray. Put the dry lids back onto the flasks. Place a new strip of autoclave tape on the tray.
6. The clean flasks are now ready for sterilization. Autoclave on gravity cycle for 45 or 60 minutes.
7. If necessary, place trays of flasks in an oven to dry or air dry. Then, place in the black "sterile" cabinet.

Large flasks (>50 ml)

Large flasks (1.5 L) are used mainly for making solid media. Since making the media involves autoclaving, these are typically not autoclaved before storage. If you need to grow a culture in a large flask, you are responsible for autoclaving it ahead of time.

Summary: autoclave (wet) → rinse/wash → normal cabinet

Detailed procedure:

1. Autoclave flasks that were used for growing microbial cultures on liquid cycle for 1 hour.
2. Dump the sterilized contents of the flasks down the drain, rinse each flask a few times with DI water.
3. Put flasks into the dishwasher (WEL: 2nd floor) and wash using cycle 7. This takes about 45 minutes.
4. If necessary, place trays of flasks in an oven to dry or air dry. Then, place in a normal cabinet on a glassware shelf.
5. Flasks can be used directly for making media, since you will be sterilizing the media by autoclaving it. If you are using large flasks to culture microbes, you will need to pre-sterilize your flasks on gravity cycle for 45 or 60 minutes.

Test tubes

Summary (test tube): bleach (wet) → dump → glass trash

Summary (plastic lid): rinse and dry → add to new test tube → autoclave (dry) → sterile cabinet

Detailed procedure:

1. Remove and rinse lids with DI water. Place lids in secondary container to dry.
2. Add beach to each test tube and allow to sit for about 15 – 30 minutes (depending on volume of solution).
3. Dump contents of test tube and place empty tube into broken glass box.

Do not put ammonia based cleaners down a sink you are pouring bleach into!

Rattler Plating Bead Cleaning Protocol

• Gather used beads.
• Add beads to a 1L flask containing DI water and contrad 70 (5% v/v).
• Cover flask with parafilm and shake at greater than 120 RPM (200 is acceptable with liquid line to 1L).
• Allow flask to shake overnight.
• Transfer beads to bead strainer.
• Rinse beads with DI water several times until all trace of detergent is gone.
• Shake beads very well to remove as much water as possible.
• After rinsing, the beads should be allowed to dry at 37C in trays until dry (overnight if well drained).
• After beads are dry transfer them into 250mL bottles and autoclave.