2018 Spring ACS: Development of an Infrared Laser Ablation Microsampling System
2018 Spring ACS: Tip-enhanced Laser Ablation Capture for Single Cell Genomics
Wavelength Dependent Atomic Force Microscope Tip-enhanced Laser Ablation
F. Cao, F. Donnarumma, K.K. Murray, Tip-enhanced laser ablation and capture of DNA, Appl. Surf. Sci. 476 (2019) 658–662. doi:10.1016/j.apsusc.2019.01.104.
Abstract
The role of laser wavelength in atomic force microscopy (AFM) tip-enhanced laser ablation was studied using an apertureless tip and a nanosecond pulsed laser. An optical parametric oscillator (OPO) laser wavelength tunable from 410 to 2400 nm was used to irradiate a gold-coated silicon AFM probe held 15 nm above the surface of an anthracene film. The absorption of laser energy by the tip at 532 nm is sufficient to melt the gold coating and increase the diameter of the tip from about 100 nm to approximately 1 µm. The ablation crater volume was measured and found to have a maximum at 500 nm and an approximately linear drop to 800 nm. Craters could not be produced between 800 and 1200 nm and the crater was slightly smaller at 450 nm compared to 500 nm. A crater rim was observed with a volume comparable to that of the crater but lower density. The mechanism of ablation is postulated to be the result of energy absorption by the tip through plasmon resonance of the gold coating followed by melting of the anthracene by ballistic, contact, or radiative heating of the anthracene film.
Louisiana Mass Spectrometry Discussion Group
A mass spectrometry discussion group for Louisiana: LAMSDG
Infrared Laser Ablation Microsampling for Mass Spectrometry Imaging
Infrared Laser Ablation Microsampling for Mass Spectrometry Imaging (CHE-1709526) is a $0.35M award to Louisiana State University and Baylor University from the National Science Foundation Division of Chemistry to support the development of new techniques for biological imaging. Thank you NSF for 20+ years of support.
Infrared laser ablation sample transfer of tissue DNA for genomic analysis
K. Wang, F. Donnarumma, S.W. Herke, P.F. Herke, K.K. Murray, “Infrared laser ablation sample transfer of tissue DNA for genomic analysis,” Anal. Bioanal. Chem. 409 (2017) 4119–4126. doi:10.1007/s00216-017-0373-z.
Abstract: Infrared (IR) laser ablation was used to remove material from tissue sections mounted on microscope slides, with subsequent capture in a solvent-containing microcentrifuge tube. Experiments conducted with a 3200-bp double-stranded plasmid DNA template demonstrated IR-laser ablation transfer of intact DNA. The transfer efficiency and the molecular integrity of the captured DNA were evaluated using Sanger sequencing, gel electrophoresis, and fluorimetric analysis. The plasmid DNA was reproducibly transferred with an efficiency of 59 ± 3% at laser fluences of between 10 and 20 kJ/m2 at a wavelength of 3 μm. IR laser ablation sample transfer was then used to ablate and capture DNA from 50-μm-thick rat brain and kidney tissue sections. DNA was extracted from the captured material using five commercial DNA extraction kits that employed significantly divergent methodologies, with all kits recovering sufficient DNA for successful amplification by polymerase chain reaction (PCR). Four sets of primers were employed, targeting one region of the CYP 11b2 gene (376 bp) and three different regions of the Snn1g gene (298, 168, and 281 bp). The PCR results were not consistently reliable when using unpurified ablation samples; however, after extraction, all samples produced PCR products of the expected size. This work expands the sampling capabilities of IR laser ablation, demonstrating that DNA can be isolated from tissue samples for genomic assays. Due to the small size of the ablation regions (1 mm2), this technique will be useful for sampling discrete cell populations from tissue sections. Graphical abstract Infrared laser ablation transfer of intact DNA from a tissue section.
Comment on: “Nominal Mass?”
K.K. Murray, Comment on: “Nominal Mass?” by Athula B. Attygalle and Julius Pavlov, J. Am. Soc. Mass Spectrom. 28, 1737-1738 (2017), J. Am. Soc. Mass Spectrom. 28 (2017) 1737–2. doi:10.1007/s13361-017-1801-1.
A recent correspondence [1] suggests that the current International Union of Pure and Applied Chemistry (IUPAC) recommendation [2] for the definition of nominal mass is flawed and should be expanded so that all possible isotope combinations for a molecule or ion can be assigned a whole number mass. The authors propose a revised definition for nominal mass as “the sum of the unified mass scale-based integer masses of its constituent protons and neutrons.” This comment is aimed at showing that nominal mass is well defined and widely used and is an essential concept in mass spectrometry. As an alternative to redefining nominal mass, it is suggested that integer mass, defined as the sum of the mass numbers of the elements comprising a molecular ion or molecule, be used.
ASMS 2017
65th American Society for Mass Spectrometry Conference on Mass Spectrometry and Allied Topics, Indianapolis Indiana, June 4 – 8, 2017
Sunday Tutorial
MALDI – Past and Future, Kermit K. Murray
Monday Poster 644
Combined Proteomic and RNA Expression Analysis of Laser Ablation Extracted Tissue, Chao Dong, Kelin Wang, Fabrizio Donnarumma, Scott W. Herke, Michael E. Pettit, Touradj Solouki,3 and Kermit K. Murray, presented at the 65th ASMS Conference on Mass Spectrometry and Allied Topics, Indianapolis, Indiana, June 5, 2017.
Monday Poster 698
Infrared Laser Ablation Sample Transfer with Conserved Biological Function, Kelin Wang, Matthew D. Baldone, Fabrizio Donnarumma, and Kermit K. Murray, presented at the 65th ASMS Conference on Mass Spectrometry and Allied Topics, Indianapolis, Indiana, June 5, 2017.
Tuesday Poster 429
Pulsed Valve Matrix-assisted Ionization, Bijay Banstola and Kermit K. Murray, presented at the 65th ASMS Conference on Mass Spectrometry and Allied Topics, Indianapolis, Indiana, June 6, 2017.
Tuesday Poster 500
Combined Solid and Liquid Matrix High Vacuum Sublimation and Evaporation Coating for MALDI Imaging, Fan Cao, Fabrizio Donnarumma, Md Amir Hossen, and Kermit K. Murray, presented at the 65th ASMS Conference on Mass Spectrometry and Allied Topics, Indianapolis, Indiana, June 6, 2017.
Wednesday Poster 362
Online Atomic Force Microscope Tip-enhanced Laser Ablation Mass Spectrometry, Md Amir Hossen, Bijay Banstola, Fan Cao, and Kermit K. Murray, presented at the 65th ASMS Conference on Mass Spectrometry and Allied Topics, Indianapolis, Indiana, June 6, 2017.
Thursday Poster 260
Infrared Laser Ablation Microsampling and Data Independent Acquisition Mass Spectrometry for Tissue Proteomics, Kelin Wang, Fabrizio Donnarumma, Carson W .Szot, Michael E. Pettit, Touradj Solouki, and Kermit K. Murray
Thursday Poster 695
Laser Ablation Capture of Formalin Fixed Paraffin Embedded Tissue for LC-MS/MS Proteomics Analysis, Fabrizio Donnarumma, Michael E. Pettit, Touradj Solouki, and Kermit K. Murray
MALDI: Past and Future: ASMS Tutorial 2017
Infrared Laser Ablation with Vacuum Capture for Fingermark Sampling
F. Donnarumma, E.E. Camp, F. Cao, K.K. Murray, “Infrared Laser Ablation with Vacuum Capture for Fingermark Sampling”, Fabrizio Donnarumma, Eden E. Camp, Fan Cao & Kermit K. Murray, J. Am. Soc. Mass Spectrom. 51 (2017) 1958–1964. doi:10.1007/s13361-017-1703-2.
Abstract: Infrared laser ablation coupled to vacuum capture was employed to collect material from fingermarks deposited on surfaces of different porosity and roughness. Laser ablation at 3 μm was performed in reflection mode with subsequent capture of the ejecta with a filter connected to vacuum. Ablation and capture of standards from fingermarks was demonstrated on glass, plastic, aluminum, and cardboard surfaces. Using matrix assisted laser desorption ionization (MALDI), it was possible to detect caffeine after spiking with amounts as low as 1 ng. MALDI detection of condom lubricants and detection of antibacterial peptides from an antiseptic cream was demonstrated. Detection of explosives from fingermarks left on plastic surfaces as well as from direct deposition on the same surface using gas chromatography mass spectrometry (GC-MS) was shown.
