What is the correct way for handling an oxygen or pH microsensor?

The most important rule is to keep the sensor fiber retracted in the cannula (or inside the protective glass tube) while handling the optical microsensor, e. g. when placing it in a micromanipulator or a laboratory support.
The sensor tip should only be extended shortly before starting the measurements or profiling. After the experiment the sensor tip of needle-type and profiling microsensors should be retracted before the sensor is removed from the sample. Strong flexing of the sensor fiber should be avoided.

For profiling applications in semi-solids (e. g. tissue, biofilms, sediments) we recommend using Profiling Microsensors combined with the Manual or Automated Micromanipulator. In case a hard surface has to be penetrated a needle-type microsensor in combination with the Manual Micromanipulator and its special safe-insert function should be used.

If a micromanipulator is not applicable in your measurement set-up, the microsensor always should be fixed to a laboratory support or a similar stable construction.

For point measurements inside samples or packaging the sensor tip has to be retracted in the needle during insertion or extraction of the sensor!

Insertion of the microsensor by hand always involves the danger, that wedging might damage or break the sensor fiber. If insertion by hand is the only possible way of application, a Profiling Microsensor should be used, as it has a more robust fiber construction. The sensor tip has to be retracted during insertion and extraction of the sensor!
Still this should be done with uttermost care!

After you have finished your experiments please clean the sensor fiber thoroughly with distilled water before it is retracted into the steel needle for storage. Otherwise dried up sample residues could lead to fiber breakage when the sensor tip is extended again.