Analytical figures of merit for a novel tissue imaging system

• Published in: Journal of analytical atomic spectrometry 2017-05, Vol.32 (5), p.144-151
• Main Authors: Straus, R. N, Carew, A, Sandkuijl, D, Closson, T, Baranov, V. I, Loboda, A
• Format: Article
• Language: English
• Subjects: Ablation; Figure of merit; Imaging; Lasers; Mathematical analysis; Micrometers; Multiplexing; Systems analysis
• ISSN: 0267-9477; 1364-5544
• DOI: 10.1039/c6ja00420b

A novel laser-ablation sample introduction system has been developed for the Fluidigm® Helios™ mass cytometer to enable highly multiplexed imaging of biological samples. Herein, we report on the analytical figures of merit for this system using a slide, coated uniformly with a metal-doped PMMA film, as a test sample. The system is based on the use of a fifth harmonic Nd-YAG laser focused to a spot size of 1 micrometer or less. A fast wash-out ablation chamber provides resolution of individual plumes when operated at a 100 Hz or 200 Hz laser repetition frequency. The system exhibits a linear response to metal concentration in the sample over 4 orders of magnitude. The variation of signals generated for 1 micrometer diameter pixels is ≤15% RSD. Pixel-to-pixel sample contamination due to redeposition of the ablated material is approximately 0.6%. The variation of the ablated crater diameter with laser energy is also explored, demonstrating a linear behaviour over a limited range of laser energies. We demonstrate the performance of a novel LA-ICP-MS system using a metal-doped PMMA film.