1. Preamble

The Center for Advanced Light Microscopy (CALM) is a TUM facility located at the TUM School of Life Sciences (SoLS) to support the advanced light microscopy needs of the scientific research groups at the Life Science Center Weihenstephan (SoLS). TUM groups outside the WZW and external research groups may also use the CALM facility according to prior agreement.

Following registration and appropriate technical instruction organized by CALM, users have access to different microscopy systems at CALM and associated scientific groups at the SoLS.

The Head of CALM together with the steering committee can make changes to the user guidelines.

The members of the steering committee are:

Prof. Dr. K. Schneitz (Coordinator of the CALM initiative)
Prof. Dr. R. Torres Ruiz (Head of CALM)
Prof. Dr. C. Schwechheimer
Prof. Dr. R. Hückelhoven
Prof. Dr. H. Luksch

CALM staff:

Prof. Dr. R. Torres Ruiz, ramon.torres@wzw.tum.de
Katrin Wassmer (Technician, part-time), katrin.wassmer@wzw.tum.de
Susanna Fink (administration, part-time), calm.plantdev.wzw@tum.de

CALM-associated microscopes are overseen by staff of the corresponding chairs/groups.

CALM website:

Further information including contact information, the available imaging systems, and the online booking calendars can be found at the CALM website at: calm.wzw.tum.de.

The CALM web site, instructions for use, manuals etc. are updated and improved from time to time. Users are expected to inform themselves about these updates.

II. Access and Booking Rules

During the booked time the user is fully responsible for the instrument.

- Users get a separate instruction for each CALM microscope. They confirm to have received this instruction with their signature. With this the instructed user is registered to work on his/her own and on his/her own responsibility with the corresponding microscope.

- Upon instruction and registration, users receive booking information and a password for the CALM microscopes. Booking is organized via an online booking system accessible via the webpage: calm.wzw.tum.de.

- Microscopes can only be booked and operated by registered and CALM-instructed users. Operation by third parties or booking by third parties is not permitted.

- An unregistered user may work at a system as long as he/she is under the constant supervision of a registered user. The registered user is then responsible for the microscope.

- The instruments can be booked up to 21 days in advance.

- During daily working hours (9 AM – 5 PM) the instruments can be booked for a maximum duration of four hours per day and user.

- Booking periods exceeding four hours require special arrangement with CALM staff.

- During evening/night hours and weekends booking time is not limited.

- There are further confocal laser scanning microscopes on the campus (“CALM-associated“ microscopes). Booking of CALM-associated microscopes requires arrangement with the corresponding Chairs/scientific groups.

III. User Fees

Users are charged a specific hourly user fee. The fees cover for costs for maintenance, repairs and upgrades on the users in proportion to their hours of usage.

CALM charges 10 € per hour per Confocal Laser Scanning Microscope but not more than 1500 € per year per chair/professorship. TUM groups outside the WZW pay 20 € and external research groups pay 30 € per hour.

Non-cancellations or late cancellation (less than 24 hours in advance) will be considered as full time booking.

IV. Liability and Insurance

The user is responsible for the microscope and the material during the reserved time slot. In case of improper operation, he/she or the respective group leader will have to pay for damage, as there is NO CALM INSURANCE for any equipment!

If no CALM personnel or responsible personnel (associated microscopes) is present, each user has to ensure that in case of an accident he/she is not on his/her own and is able to call for help. This especially applies when working during off-time hours (5 PM - 9 AM).

V. Precautions and Rules for Running the Microscopes


- Turn on all lasers you’ll need during initial start-up (but only those).

- When switching a system on or off, please consult the (updated) instructions on the webpage. Always refer to them as they may contain new information.

- Since switching lasers and lamps off/on within short intervals drastically reduces their lifetime a 2-HOUR-RULE applies!

Lasers and fluorescence bulbs must remain turned on (STANDBY mode), if the time interval between two slots is 2 hours or less (lasers that are not used within the next 2 hours should be switched off).

- To ensure that systems are switched off properly you have to double-check the actual booking status of the instrument at the end of your time slot in the online booking system (the user after you might have deleted her/his booking last minute).

- If you remove your time slot on short notice, i.e. during the day of your booking, be aware that the system might have been left on for you. THE USER IS RESPONSIBLE to properly switch the system off to avoid that it remains turned on over longer periods of time without being used! YOU ARE ALSO RESPONSIBLE to properly switch off the system or to inform/to hand it over to the next colleague if you quit earlier!

- If a system has just been switched off right before you planned to use it (you see that in the booking schedule) provide the lasers and lamps with at least 30 minutes time to cool down before re-starting the system.


- Once you turn the mercury lamp on, it needs to remain on for at least 30 minutes before being turned off. If not otherwise indicated (e. g. Olympus FV3000), once it’s turned off, it needs to be off for at least 30 minutes before being turned on again. If the mercury lamp has passed the maximum hours of use do not turn it on! The bulb must be replaced.

- After switching off the mercury lamp it remains very hot for some time. Be careful to not let the microscope cover touch it!


- Please handle the objectives with utmost care (they are the most valuable parts of the microscopes in terms of good images and costs!).

- The type of an objective (air, water, oil, silicone; immersion versus dipping lens; magnification) is explicitly indicated on the objective housing and in the software.

- The objective revolvers must always be lowered and centered BEFORE the stages are moved or homed (calibrated) when switching on a system and after usage.

- After finishing your work position the objective revolver to a low magnification lens (usually 10X or lower) set. In addition, always set the objective revolver to the 10X position when you want to remove a slide/coverslips from the holder.

- Be extra careful not to touch the objectives!

- Focus carefully to avoid crashing into the coverslips (check by eye, if objective is still in safe position).

- Oil objectives have to be cleaned with provided lens paper after usage. Do not wipe with kimwipes and do not wipe too much on the lens itself. On inverted microscopes carefully clean the objective housing around the lens to avoid oil rinsing down into the optical system below the objective.

- Only use oil provided by CALM for the individual microscopes. Clean the coverslips of your samples upon imaging them on different systems with different oil. Mixing of oil of different brands or oil and water/medium can cause damage to lenses (check self-assembled cell chambers for live cell imaging for leakage!).

- Air/water objectives must not get in contact with oil – if you realize that an air objective has got into contact with oil, please contact CALM staff.

- There are possibly more objectives available than mounted on the microscopes (see VIII CALM microscopes).


- The different microscopes are all located in S1 facilities. Thus, the corresponding laws and regulations apply and only S1 material can be handled in these rooms. The users are required to obtain permission to work under S1 conditions and to abide by the known S1 regulations (as publicized in the annual S1 instruction). Users who do not follow these instructions will be banned from using the microscope.

- Please keep the CALM rooms tidy, clean spills with ethanol and remove any personal material before leaving.

- Access to CALM facilities is provided by numerical code for the panels at the doors. Users get the code when instructed. 

- Please make sure to lock the doors if you are the last to leave the facility.

- If systems are encountered in a defective condition please inform the staff immediately BEFORE using the system.

- Removal of any CALM material (objectives, immersion oil, etc.) from any microscope room or moving material between rooms is strictly forbidden. Users who do not follow these instructions may be banned from using the microscope.


Every microscope has an associated logbook. The user is required to register and to record date and time (start and end of session) as well as the use of laser and/or mercury lamp and which objectives were used. 

The user has to confirm that he/she cleaned the objectives at the end of the session. Users who do not follow these regulations will be not be allowed further access to the microscope.

VI. Data Storage and Publishing

After image acquisition, data have to be uploaded to the remote storage of the user’s workgroup, which is maintained by the InformationsTechnologie Weihenstephan (ITW). The ITW provides a temporary storage “forecourt“, from which data can be transferred to the own computer. Alternatively, there is the possibility to use an OMERO database on the CALM server at the ITW.

Unless otherwise instructed by CALM, it is absolutely forbidden to use USB sticks for data transfer! The CALM facility cannot take any liability for any data stored on the CALM computer. Data stored on a CALM computer may be deleted without warning.

Images and data that have been generated with CALM microscopes might become part of publications, Ph.D. theses or other types of publications. In this case, it is mandatory to acknowledge the use of the CALM facility in the corresponding publication and a brief note needs to be send to the head of CALM.

VII. Warnings and Information

We control for proper handling/booking of the instruments and we record who has violated the guidelines (you’ll be informed if you got a record).

Please be aware of the following terms:

- if a user refrains from using his/her time slot for a microscope on short notice and another user steps in, the second user has to indicate this in the booking schedule. If the booking under her/his name is missing he/she gets a first warning. Upon the second incidence, further usage of the CALM facility may be prohibited.

- a user gets a record if she/he doesn’t shut down the system properly - either because she/he forgot to switch the system off after her/his time slot or upon spontaneous cancellation of her/his time slot without controlling if the system has been shut down by the previous user. In any case the period will be regarded as booked time.

- information about changes at CALM systems (updates, new equipment, actual status of systems, upcoming events) will be posted on the CALM web page and may also be posted at the microscope itself. Users are responsible to get informed about any changes regarding the microscopes and regulations.