Aseptic Technique

Aseptic technique is, in short, a technique to prevent items from becoming contaminated while you’re working with them. Good aseptic technique is essential for producing homemade HRT and is a primary reason that making HRT is a highly skilled practice. Without training, you will cause items you’re working with to gain bacterial contamination.

Many parts of this page are copied directly from Tyger’s DIY guide.

Text like this is from Tyger.

Why this is particularly important

After reading about the sterilization theory you will learn that HRT is quite sensitive, and that it must be sterilized solely through the use of filtration and aseptic technique. There is no final heat sterilization step that can be safely performed on HRT, meaning we have to achieve sterilization partially through our very careful handling of materials.

Recommended watching

• Aseptic Technique video 
• Hand hygine and garbing for compounding pharmacy 
• Series part 1: hygine, garbing, cleaning 
• Series part 2: sterile work 
• Possibly redundant series 

Hand washing

Learn how to properly wash your hands 

Bacterial shedding

Most objects are “shedding” bacteria at all times, constantly moving it around, transferring it, and dropping it. If you have an open vial on your work bench, and you accidentally hover your hand or something else non-sterile over it, you have put the open vial at risk of collecting bacteria simply by it falling into the vial.

For this reason the medium and large guides will always have you working in a still air box or a laminar flow hood respectively.

Never put your hand or another object above an item that is intended to be sterile.

Bacteria is your number one enemy. Airborne bacteria is all around you. As bacteria is generally heavier than air, it tends to sink downwards and land on surfaces, so hold sterile containers at an angle and cover them with tin foil… while you are not using them. The places in your house with the most bacteria are probably on your body – your hands and fingertips especially. Imagine you are in a lab, learning about micro-organisms. If you were to press your fingertip into a petri dish and incubate it, you would see a garden of bacterial colonies bloom, growing to form an exact copy of your figerprint in pale shades of yellow and green. Wash your hands for a few seconds and perform the experiment again – you no longer see the fingerprint, but the dish still produces plenty of spots where your finger was. Finally, wash your hands thoroughly for 40 seconds and perform the experiment a final time. You now have a plate with only one or two bacterial colonies growing on it.

Alcohol spray bottle

You should have a spray bottle filled with (ideally sterile) isopropyl alcohol (IPA) 70%¹. Stronger concentration is not better . The 30% water content is essential for helping the IPA kill bacteria. Higher concentrations are generally better for applications where quick evaporation is useful, like cleaning electronics.

Your IPA spray bottle should be on your bench ready for use throughout your brew. Periodically you should spray your gloved hands with the IPA and rub them together to help kill any bacteria your gloves have picked up.

You can also use the spray bottle to spray down any non-sterile items that need to go into your still air box or laminar flow hood.

Brewing while sick

Is a major no. This includes colds, flus, covid, vomiting, or diarrhea. This includes you, anyone you live with, and anyone who lives at the location you’re brewing at. It’s not worth the risk, wait until everyone is feeling better.

Brew topicals if you need to brew faster.

Continuing Education

The above information is not adequate for understanding aseptic technique. It’s just some ideas I’ve put together. Watch the videos above and continue to read about this on your own.

References