From the invisible to the visible world and back

In the microbiology the air tightness is  a fundamental parameter, be cause the microrganisms in a sample are too much delicate, and an exposition to the common ambient can be dangerous, cause of this reason is neccesary in a microbiology lab, have an Autoclave.

The autoclave is a device that we can use to close hermetically a sample with a bacteria colony for an example. The use of this device is so important in a investigation and it is very rare not have one.

There are physical, chemical, and biological indicators that can be used to ensure that an autoclave reaches the correct temperature for the correct amount of time. If a non-treated or improperly treated item can be confused for a treated item, then there is the risk that they will become mixed up, which, in some areas such as surgery, is critical.

Chemical indicators on medical packaging and autoclave tape change color once the correct conditions have been met, indicating that the object inside the package, or under the tape, has been appropriately processed. Autoclave tape is only a marker that steam and heat have activated the dye. The marker on the tape does not indicate complete sterility. A more difficult challenge device, named the Bowie-Dick device after its inventors, is also used to verify a full cycle. This contains a full sheet of chemical indicator placed in the center of a stack of paper. It is designed specifically to prove that the process achieved full temperature and time required for a normal minimum cycle of 134 °C for 3.5–4 minutes.

 To prove sterility, biological indicators are used. Biological indicators contain spores of a heat-resistant bacterium, Geobacillus stearothermophilus. If the autoclave does not reach the right temperature, the spores will germinate when incubated and their metabolism will change the color of a pH-sensitive chemical. Some physical indicators consist of an alloy designed to melt only after being subjected to a given temperature for the relevant holding time. If the alloy melts, the change will be visible.

So the autoclave is an amazing instrument that sometimes the people forget, or don't know nothing about it, if we keep in mind we may have other uses and applications for it. I like to think about the instruments that have a normal use but in the bottom of that instrument we can found a lot of things that we never could imagine, so keep in mind on this day and every day!.