Device to apply a coating on tissue samples for MALDI imaging Holly Liske Laura Piechura Kellen Sheedy Jenna Spaeth Amy Harms, PhD UW Biotechnology Center Brenda Ogle, PhD Department of Biomedical Engineering

Presentation Overview Background of MALDI imaging Project motivation Problem statement Design criteria Design matrices Final design Budget evaluation Future work

MALDI-MSI

Data Acquisition from MALDI-MSI Alanine, neuropeptide in crab brain m/z = Valine, m/z = Alanine Valine Greg Barrett-Wilt, PhD., UW Biotechnology Center

Benefits of MALDI-MSI Analysis of entire sample in one reading Previous knowledge of molecular composition is not necessary Allows for investigation of disease formation, progression, and treatment

Matrix Application Matrix application is vital for quality image resolution Must contact sample as fine, liquid mist Current procedure involves manual application with airbrush 100µm raster step Greg Barrett-Wilt, PhD., UW Biotechnology Center

Problem Statement Sample preparation methods MALDI-MSI are difficult to control Requires accuracy and precision A device to apply a fine, uniform coating of light- absorbing compounds

Project Motivation Objective 1: Simplify matrix application, facilitate MALDI Objective 2: Centralize a reliable tool at UW Biotechnology Center Implications for campus-wide, even global, research

Design Criteria Spray an even coating of matrix over an 81cm x 123 cm tissue sample Adjustable spray aperture, air pressure and positioning of the plate and sprayer Enclosed in a casing and operable within a fume hood

Design Matrix Adjustment Several variables controlled by many independent components Sprayer Method of application Enclosure Orientation Created a component matrix to decide final design

Component Matrix VerticalHorizontal Orientation Detached covering Integrated covering Fume hood Enclosure Stationary sprayer, Movable plate Movable sprayer, Stationary plate Method of Application Produce irrigation system Pneumatic sprayer Nebulizer Nozzle- valve with pressure vessel Automatic Spray Gun Sprayer IdeasFeature

Criteria for ranking Reliability Adjustability User interaction Cost Maintenance Ease of manufacture Ranking System (1-5), highest = best

Mega Matrix Spraying Component Total Ease of Manufacture Maintenance Cost User Interaction Adjustability Reliability Produce irrigation system Pneumatic sprayer Automatic Spray Gun Nozzle-valve and pressure vessel NebulizerRankCriteria

Mega Matrix Method of Application Total Ease of Manufacture Maintenance Cost User Interaction Adjustability Reliability Movable Plate Stationary Sprayer Stationary Plate Movable Sprayer RankCriteria

Mega Matrix Enclosure Total Ease of Manufacture Maintenance Cost User Interaction Adjustability Reliability Removable CoverIntegrated CoverFume HoodRankCriteria

Mega Matrix Orientation Total Ease of Manufacture Maintenance Cost User Interaction Adjustability Reliability Vertical SprayHorizontal SprayRankCriteria

Final Design Model 1.Automatic Spray Gun 2.Conveyor 3.DC Timing Motor 4.Integrated Polyethylene Box

Budget Evaluation $ budget limit Breakdown Air Spray Gun: $ Motor/Conveyor: $45.00 Enclosure material: $45.00 Other small parts: $40.00 Total Estimate: $ (under budget)

Future Work Final Design modifications Order materials Build prototype Test in client’s lab

References Ashcroft, Alison. University of Leeds Astbury Centre for Structural Molecular Biology. “An Introduction to Mass Spectrometry.” Barrett-Wilt, Greg. University of Wisconsin Biotechnology Center. Personal interviews. Caprioli Research Laboratory Center. Vanderbilt Medical Center. Khatib-Shahidi, Sheerin. “Direct Molecular Analysis of Whole-Body Animal Tissue Section by Imaging MALDI Mass Spectrometry.” Analytical Chemistry. 2006, 78(18) Sugiura, Yuki. “Two-Step Matrix Application Technique to Improve Ionization Efficiency for MALDI-MSI.” Analytical Chemistry. 2006, 78(24)

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