Infrared Laser Ablation Microsampling for Small Volume Proteomics

J Am Soc Mass Spectrom. 2022 Jun 1;33(6):1003-1010. doi: 10.1021/jasms.2c00063. Epub 2022 May 10.

Abstract

Infrared (IR) laser ablation was used to remove localized tissue regions from which proteins were extracted and processed with a low volume sample preparation workflow for bottom-up proteomics by liquid chromatography tandem mass spectrometry (LC-MS/MS). A polytetrafluoroethylene (PTFE) coated glass slide with 2 mm diameter microwells was used to capture ablated rat brain tissue for in situ protein digestion with submicroliter solution volumes. The resulting peptides were analyzed with LC-MS/MS for protein identification and label-free quantification. The method was used to identify an average of 600, 1350, and 1900 proteins from ablation areas of 0.01, 0.04, and 0.1 mm2, respectively, from a 50 μm thick rat brain tissue section. Differential proteomics of 0.01 mm2 regions captured from cerebral cortex and corpus callosum was accomplished to demonstrate the capabilities of the approach.

MeSH terms

  • Animals
  • Chromatography, Liquid
  • Infrared Rays
  • Laser Therapy* / methods
  • Proteins / analysis
  • Proteomics* / methods
  • Rats
  • Tandem Mass Spectrometry / methods

Substances

  • Proteins