MALDI-UP An Open Catalog for Databank Entries by Users for Users, at maldi-tof-ms-user-platform.ua-bw.de

Report from a day in the lab

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MALDI TOF MS
MALDI TOF MS

A new means of professional exchange

The use of MALDI-TOF Mass Spectrometry (MALDI-TOF MS) in research and routine laboratories is rapidly growing. The instruments combine matrix-assisted laser desorption/ionization (MALDI) with time-of-flight (TOF) mass spectrometry (MS). Large biopolymers such as proteins from microorganisms, fish or meat can be relatively softly analyzed with this method.

This technology has been used mainly for the differentiation of bacteria and other microorganisms in clinical microbiology, veterinary medical diagnostics and in food microbiology. An unknown microorganism can be identified by comparing its mass spectrum to that of a reference in a database. This database thus plays a central role in the identification.

The systems (consisting of both hardware and software) employed by most users offer not only an extensive databank supplied by the manufacturer, but also allow for the addition of one’s own data. These can be transferred within the device platform, making it possible to fill in diagnostic gaps more quickly. In our experience, this is especially valid for a series of special microorganisms from veterinary medical microbiology. There are few databases available for other areas of research, such as the species identification of animal meat via MALDI-TOF MS, although a wide circle of users is interested in them.

In order to make information regarding high quality database entries available from users for users, we have set up an „open catalog“ in the Internet, under http://maldi-tof-ms-user-platform.ua-bw.de and under the shortened version http://maldi-up.ua-bw.de.

The list will be maintained on a subdomain and updated at fixed in-tervals within the framework of the website „UA-BW“.

Illustration 1: Screen shot of the Homepage

MALDI-TOF MS User Platform
Abbildung 1: Screenshot der Startseite

The catalog in MALDI-UP offers uniformly presented, comprehensive information regarding species names, isolate numbers and specimens, as well as the designation of isolates (e.g. molecular biological identification, biochemical data) and technical details of the entries (instrument, cultivation, preparation, etc.). The summary of data entries, and especially the contact information for the owner of the entries, shall be presented in this manner. No actual spectra will be available for free download on MALDI-UP. The copyrights to the data and the updating process of the equipment manufacturer will thereby not be affected.

The catalog in MALDI-UP is open for users, subject to the conditions stated on the homepage regarding the publication of information on one‘s own database entries. The catalog (in Excel) can be thusly downloaded and new rows of data can be added in the proposed format. After the new data is sent to maldi-up@ua-bw.de, it will be checked, any missing information will be requested, and finally the newly added rows will be included in the next update of the catalog.

Every user that provides information makes his or her contact data available and responds to any enquiries about the data him or herself. In this way, the data-providing user can steer information exchanges with his or her colleagues. This concept was developed with assistance from employees at CVUA Stuttgart and the Hessen State Laboratory. We can be reached for comments and suggestions at maldi-up@ua-bw.de.


Illustration 2: Schematic Structure of a MALDI-TOF Mass Spectrometer

MALDI-TOF Massenspektrometer
Abbildung 2: Schematischer Aufbau eines MALDI-TOF Massenspektrometers

Illustration 3: Typical mass spectrum (black) and the resulting calculated reduced spectrum (main spectra projection, MSP, blue)

Typisches Massenspektrum und daraus berechnetes reduziertes Spektrum
Abbildung 3: Typisches Massenspektrum und daraus berechnetes reduziertes Spektrum

Photo Credits: CVUA Stuttgart

Authors:
J. Rau, R. Sting (CVUA Stuttgart); T. Eisenberg (Hessen State Laboratory, Gießen)
Translation: Catherine Leiblein