LAESI DP-1000 Ionization Source

Overview:
The DP-1000 Laser Ablation Electrospray Ionization (LAESI) source has been developed to allow comprehensive mass spectrometric (MS) analysis of biological samples. This fully integrated source contains all components necessary to perform a LAESI-MS analysis, including a mid-infrared (MIR) laser, electrospray emitter, high voltage power supply, syringe pump, dual cameras for sample imaging, an integrated ultra-precision x,y,z stage, and a temperature-controlled sample nest. In addition, a complete software suite has been developed to support LAESI-MS data collection and analysis.

Laser Module:
The MIR laser outputs a wavelength of 2.94 µm that matches the absorption of the stretching mode of the O-H bond in water. The 5 ns pulsed laser has an output energy of 1.0 mJ and can span a range of frequencies from 0.1 Hz to 10 Hz. In addition, a spot size of 200 µm allows for excellent resolution for imaging applications.

Electrospray Module and High Voltage Power Supply:
The electrospray module uses standard stainless steel emitters for extended lifetime and durability, and our emitter module allows the option of using a sheath gas for increased desolvation and sensitivity. The syringe pump provides flow rates from 100 nL/min to 5 mL/min for optimum flexibility. The integrated high voltage power supply can output 0 to ±5000 V, allowing both positive and negative ion modes of analysis.

Sample Imaging Module:
The DP-1000 also includes two integrated cameras: a wide angle camera used for capturing images of the entire sample and a targeting camera used for a 5 mm near-field magnified view of the ablation spot. Using the wide-angle camera, a user can quickly obtain an image of the sample being analyzed and use this image to select the analysis location(s) or regions of interest. Once an analysis has begun, the targeting camera can be used to view the actual sample analysis in real-time. The targeting camera is focus-matched with the MIR laser to provide convenient focal alignment and robust ablation performance.

Sample Nest and Stages:
The sample nest of the DP-1000 is capable of accommodating a 96, 384, or 1536 well plate with standard 127.76 x 85.48 mm dimensions. Aluminum tissue plates allow analyses of standard 1″ x 3″ or 3″ x 4″ slide mounted tissue sections. The DP-1000 sample nest has a 4-quadrant Peltier thermoelectric cooler that is controllable from -10 to +60 °C. In the cooling mode, frozen tissue sections will maintain their integrity at -10 °C, and well plate samples can be cooled to minimize evaporation at +4 °C. In the heating mode, kinetic studies can be performed at elevated temperatures up to +60 °C. Custom translation stages provide travel for analysis over the entire sample plate footprint (x, y, and z translation stages have 141, 91, and 24 mm of travel, respectively). The focusing lens uses a custom stage to provide 23 mm of travel for automated control and maintenance of the laser and visual targeting focus.

The LAESI-MS Software Suite:
The DP-1000 is controlled by our fully functional LAESI Desktop Software™ (LDS) platform. The LDS software enables everything from quick discovery experiments in the Interactive Mode to more sophisticated LAESI-MS method development and sample analysis in the Project Mode. In addition, our ProteaPlot™ post-processing software is used to analyze and interpret the LAESI-MS data after collection. This unique software can create publication-quality 2D and 3D images (ion maps) with up to four distinct m/z on a single plot while maintaining all of the functionality of traditional MS viewing software.