Data acquisition whole body imaging

Nowadays, pulsed, frequency tripled Nd YAG UV lasers (355 nm) are usually employed for MALDI experiments with a repetition rate of 1000 Hz in commercial instruments for sufficient data acquisition. In MALDI-IMS, the resolving power for application strongly depends on the sample preparation step (e.g., matrix crystal size), stepper motor accuracy, and laser spot sizes. To achieve MALDI-IMS to a practical resolution, the laser spot size of 20 pm is usually used. Therefore, the time needed to obtain images from a sample depends on the number of analyzed spots, the repetition rate of the laser (Hz), and the data collecting and processing speed of computers. For example, imaging a whole-body mouse or rat section with current commercially available MALDI mass spectrometers equipped with lasers operating at 1 kHz would take 2-4 h. 

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