Abstracts and Presentation Schedule Event ended
Abstracts are listed in order of author presentations for Tuesday, June 11 and Wednesday, June 12. The presentation schedule is subject to change; check this page regularly for updates.
TUESDAY, JUNE 11
MORNING
The World’s Best (Old) and Worst (New) Microscopy — Video Presentation
Brian J. Ford
Today we can compare the way the pioneers viewed and recorded their specimens with scandalous examples of poor microscopy from today’s laboratories. The views recorded by the first microscopists addressed specimens and structures that nobody had ever viewed in that way before. They used the simplest of equipment. Single-lensed microscopes were the only means available to obtain the higher magnifications necessary to visualise microorganisms and details of the living cell. In spite of these obstacles, Hooke and Leeuwenhoek obtained astonishing results. We can now identify the specimens they viewed and compare them with the drawings they made. By contrast, we now have a wide-ranging understanding of microscopes, microtechnique, and the microscopic world, yet some modern microscopists cannot even emulate the standards of their predecessors over three centuries ago.
From Meters to Nanometers: Surface Textures Can be Appreciated at Extreme Scales
Kevin Brady — K.A. Brady & Associates LLC
While surface textures can be essential in mechanical functions like adhesion and friction, they can also be beautiful. Surfaces can appear smooth at one scale while appearing extremely rough at other scales. There are many ways to measure and represent surface roughness. A few more common methods will be presented together with images of surface textures at various scales.
Comparison of Soil Color Determination Methods
Ethan Groves (presenting author) and Christopher S. Palenik — Microtrace LLC
Color is often the first characteristic observed in a soil characterization. At the start of a forensic comparison, soil colors are evaluated to determine whether the two samples can be excluded as originating from a common source or if additional analysis to evaluate this possibility is warranted. Soil color determination is often accomplished by visual examination and manual comparison to standard color chips. However, additional methods include spectrophotometric measurement or image processing. Color data for a set of 180 soils from North Carolina were determined using each of these three methods. This presentation will discuss benefits and limitations of each approach, evaluate differences between them, and demonstrate the discriminating power of color as it applies to forensic soil comparisons.
Characterization of Nuclei Shapes in Human Hair Roots
Joseph Donfack — Research and Support Unit, Federal Bureau of Investigation Laboratory Division
In this study, human scalp hair roots were stained using the DNA binding dye 4', 6-diamidino-2-phenylindole (DAPI), and visible nuclei were counted. The DAPI-stained nuclei were visualized via high-magnification fluorescence microscopy. A variety of nuclei shapes and sizes were identified, including ellipsoidal, spheroidal, elongated, and trailing. The diversity of nuclei shapes and sizes described here can serve as a practical guide to assist forensic examiners in conducting examination of DAPI-stained hair roots and DAPI-stained nuclei counting. To maximize accuracy and efficiency of nuclei counting, the examiner must be aware of the different nuclei shapes that may or may not be present simultaneously in a single hair root sample. In addition, awareness of different nuclei shapes allows examiners to better distinguish true nuclei from staining artifacts or other features that have no consequence in downstream DNA analysis. The ability for a hair examiner to be aware of the possible general shapes of the nuclei discussed in this study may result in a more accurate nuclei count to assist in the routing of hairs for the appropriate DNA analysis.
Polysaccharides Differentiation in a Pharmaceutical-Technical Context
Jan Burmeister (presenting author) — Chemie AG, Berlin, Germany
Maike Josephine Haendly — Hochschule Zittau/Görlitz, Zittau, Germany
Polysaccharides are used by the pharmaceutical industry for a variety of applications. Prominent groups of substances used in such contexts are starches and celluloses, as well as their polymer-analog derivatives. The usefulness of a microscopical and microchemical approach to solve issues in development and manufacturing of solid oral dosage forms containing these excipients will be discussed. Polarized light microscopy as well as morphological and reactivity features of these substances prove useful in problem-solving. In addition, chemical staining reactions developed in the field of pulp and paper analysis, e.g., ISO 9184 standards, are useful in this pharmaceutical context.
Inverting the Becke Line Color Chart in Figure 5–9 in Bloss’s Optical Crystallography
Wayne Moorehead — forensic TRACE
Identification of unknown particles using the immersion method with a polarized light microscope was taught in a tier-one university forensic microscopy course using Optical Crystallography by F. Donald Bloss as the foundational text for understanding the theory of optical properties observed in the microscope. A chart from the text, Figure 5–9, was confusing to students. By inverting the chart, the students’ observations of optical properties appeared more consistent with the information contained in the chart. Thus, the inverted chart is more useful toward determining the refractive index of an unknown particle.
TUESDAY AFTERNOON
Foreign Particles in Pharmaceuticals: A Holistic, Pharm-to-Table Approach
Kelly Brinsko Beckert — Microtrace LLC
The identification and sourcing of foreign particles in pharmaceutical products is a critical part of quality control for any drug company, but many lack the resources to 1) isolate and 2) identify these often very small particles. Our laboratory receives and analyzes a number of such particles every year, and they can be found in a plethora of pharmaceutical matrices, including tablets, capsules, gels, liquid-filled vials, glass cartridges, dermal patches, medical devices, and raw materials, to name a few. In a series of illustrative case studies, this talk will discuss some of our techniques for particle isolation from challenging samples, the subsequent analysis and identification of the foreign particles, and their comparison to potential source materials.
Two Examples of Building Sealant and Adhesive Failures
Andrew A. “Tony” Havics — pH2 LLC
Facades of buildings are measured in the thousands of square meters or thousands of square feet. All of this constructed environment is negatively affected by poor sealant durability. Similarly, interiors of building also contain numerous uses of adhesives and sealants. Two cases illustrate some common approaches to failure. The first is the failure of adhesive material holding large glass panels. The first case included visual and textural check of the material, Shore hardness testing, Fourier-transform infrared spectroscopy (FTIR) analysis, and polarized light microscopy (PLM) analysis. The second case involved testing of polymer-base (PB) material from expansion joints suspected of being damaged from a hurricane event. For the second case, testing included tensile testing, Shore hardness testing, light microscopy and materials characterization, dimensional evaluation, FTIR, and pyrolysis gas chromatography-mass spectroscopy (GC-MS) analysis.
Microplastics, Macro Problems: Method Development Considerations for Routine, Objective Microplastic Analyses
Otyllia Vercelletto (presenting author) and Christopher S. Palenik — Microtrace LLC
Microplastics (MPs) represent an ever-evolving field of study with an immense body of literature to address this growing global concern. Despite this body of literature, the development and implementation of a routine microplastics workflow for real-world samples is often thwarted by limitations that arise regarding MP isolation, detection, identification, and/or quantitation. To overcome the complexities associated with MP isolation and analysis from dirty matrices, we attempt to adapt and borrow from the strengths of existing literature in pursuit of an approach that is holistic, objective, and time-conscious.
The approach we have arrived at consists of three parts, namely particle isolation and cleanup, automated analysis, and data interpretation. Our work has been honed using real-world water and sediment samples from the Milwaukee area in collaboration with the USGS. This presentation will discuss method development for large-scale routine MP analysis, validation efforts, and complexities encountered along the way.
A Collection of Historical Polarizing (Petrological and Petrographic) Microscopes and Accessories
Skip Palenik — Microtrace LLC
I have been interested in the microscope as analytical instrument since I received my first one on my eighth birthday. That Gilbert microscope set included a set of polarizers (Polaroid Jr.), and thus I learned to appreciate the benefits of polarized light from my earliest introduction to and experiments in analytical microscopy and microanalysis. As is the case still today, a polarizing microscope then, as now, was beyond the reach of a child and it wasn’t until much later that I acquired my first monocular polarizing microscope — a gift from my soon to be employer, Dr. Walter C. McCrone — when I returned home from my hitch in military intelligence in the mid-1960s.
It was at this time, shortly after going to work for my boyhood hero, that I had the opportunity to buy my first polarizing microscope. This was a beautiful, brass, Bausch & Lomb monocular, and my family and I were unhappy with the deal for different reasons: 1) I had to sell the Rogers drum set that I had played in my band (Strangeways) before I enlisted, 2) it did not have a Bertrand lens, 3) it became the cornerstone of my collection of antique and vintage polarizing microscopes, and 4) it was the beginning of an expensive hobby.
This presentation will introduce the audience to a few of the microscopes, accessories and slides that comprise this collection in the hope that Inter/Micro attendees may find them of some interest with respect to both their beauty and utility. The instruments chosen for this presentation have been selected based on their appearance and importance for the gradual development and improvement of the polarizing microscope over time.
Economical Videomicrography
Sebastian Sparenga — McCrone Research Institute
With the constant improvement in digital technology, it is now faster, easier, and cheaper to record and edit quality video through the microscope. This talk will discuss several low-cost options for recording video as well as how to perform basic video editing with budget-friendly software.
Who Shot Whom? Untangling a Valentine’s Day Mystery
Jim Dunlop — Kalamazoo County Sheriff’s Office
On Valentine’s Day 2017, dispatchers received a 911 telephone call from a rural Kalamazoo County residence. The female caller, who lived in a house with her husband and 5-year-old son, stated that her husband had shot her before turning the gun on himself in an apparent murder-suicide.
The woman told police a hair-raising account of how she had disarmed her husband during his initial assault and how he then acquired a second firearm with which he shot and wounded her. She said that she had been left unconscious by the gunshot wound, and when she awoke, she discovered that her husband, believing that he had killed her, had then taken his own life.
While processing the crime scene, an array of tiny particles were discovered which, when analyzed, became crucial to reconstructing the events that had transpired in the house. This presentation will focus on trace evidence analysis of those particles, with an emphasis on polarized light microscopy, micro-infrared spectroscopy and scanning electron microscopy, which were instrumental in resolving this case.
WEDNESDAY, JUNE 12
MORNING
The Pioneers’ View: What Were the First Microscopists Observing? — Video Presentation
Brian J. Ford
How did the earliest microscopists make sense of what they saw? Can we rely on their observations? Research is revealing precisely how images from centuries ago can be reconciled with the appearance of a specimen in life. Modern methods of superimposition allow us, for the first time, to blend images from the 1600s with those from the present day. The results provide an astonishing glimpse into the birth of microscopy. As these findings attract increasing global scholarly interest, they are being emulated elsewhere, though the lack of expertise in many commentators means their understanding is no match for the sheer ingenuity of their predecessors from over three centuries ago.
Analysis of Synthetic Wig Fibers by Microspectrophotometry
Thomas A. Kubic (presenting author) — John Jay College CUNY and Thomas A. Kubic and Associates
Jaclyn Beshlian — John Jay College and New York City Police Department Crime Laboratory
The absorbance spectra and fluorescence spectra employing a number of excitation wavelengths from green to near ultraviolet were studied on a number of synthetic wig fibers by microspectrophotometry. The goal was to determine the relative discriminating ability of these analytical techniques.
A synthetic fiber was employed, in place of a human hair, to minimize the effects of hair dye absorption. This polymer has been used as a material to improve the appearance of head hair. All 20 samples evaluated can be classified as various shades of brown so that discrimination was most difficult. A colorless (white), red, and black sample were also determined. Reproducibility of calibration over a six week period was also evaluated.
For this small set of exhibits, the fluorescence spectral data appear more discriminatory. Representative infrared (IR), and visible microspectrophotometry data will be presented.
Proof and Causation: Enter the Microscope
Andrew A. “Tony” Havics — pH2 LLC
The microscope, under adept hands, can ascertain the attributes of objects both big and small. These attributes include size, color, morphology, composition, and structure. It is various iterations of these attributes that allows a microscopist to entertain various levels of proof. These levels of proof range from simple detection to highly certain causation and rely upon1) at least one (if not more) microscopical relational aspect, 2) a certain amount of knowledge acquired through examination, and 3) some level of inference. Inference was the focus of a recent book by Brooke Kammrath and John Reffner, Solving Problems with Microscopy, Real-Life Examples in Forensic, Life and Chemical Sciences. I propose various levels of certainty, in terms of causation, that can be acquired through the use of microscopy and will provide examples of each based on these three underlying forms of support.
The Refractive Index Range of Chrysotile
L.A. Thomas (presenting author) and G.K. Druschel — Department of Earth Sciences, Indiana University, Indianapolis
Determining precise optical properties of chrysotile is critical because polarized light microscopy (PLM) is being used to characterize amounts of chrysotile in talc matrices, and the degree to which these properties may or may not overlap will determine the effectiveness of PLM in differentiating chrysotile from talc. This study reports the results of a comprehensive characterization of refractive index across the visible range for a suite of 16 chrysotile samples from North America, Europe, Russia, and Africa. The technique that was used applied the concepts of the double-variation method, but it substituted commonly available 10 nm bandpass filters centered on 486.1, 589.3, and 656.3 nm in lieu of the slide monochromator used by Bloss and Gunter (1, 2) and a standard microscope slide/coverslip preparation rather than a spindle stage. This setup better represents the materials readily available to microscopists doing this work. Refractive index was determined by the movement of a bright Becke line into the material and “disappearance” of the fiber’s edge in specific refractive index liquids (Cargille Labs, Inc.) at specifically controlled temperatures. Observations at each wavelength were used to determine Cauchy constants and compute the Cauchy curve from 470 to 670 nm. Refractive index glass standards (Cargille set M-18) provided a check on the refractive index liquid’s calibration. Central stop dispersion staining images, captured across the refractive index range of the liquid, provide another approach to characterizing refractive index; comparisons will be presented. We also determined the chemistry of the samples with SEM-EDS, and microspectrophotometer analysis. The observed mean values decrease from 1.5617 at 486.1 nm to 1.5514 at 589.3 nm to 1.5472 at 656.3 nm, with standard deviation of ≈ 0.0035 at all three wavelengths. Developing this technique involved considerable exploration of proper focus and selection of appropriate targets within the field of view and informs proper ways to determine chrysotile's optical properties in talc matrices with precision.
1. Bloss, F.D. The Spindle Stage: Principles and Practice, Cambridge University Press, 1981.2. Gunter, M.E. “MSA at 100 and Why Optical Mineralogy Still Matters: The Optical Properties of Talc, ” American Mineralogist, 107, pp 1–14, 2022.
Lessons in Fiber Chemistry
Jason C. Beckert — Microtrace LLC
This presentation will focus on a forensic fiber comparison that was part of a double homicide investigation and prosecution. It will discuss aspects of the case from fiber searching and collection through laboratory analysis and, ultimately, testimony. The laboratory analysis was performed without any case-specific contextual information, as is sometimes recommended, certainly, by various members of the criminal justice system. Despite some initial difficulties, the comparison was completed and indicated a strong association between the questioned and known fibers. However, once the context surrounding the fibers was revealed, this question remained: what is the ultimate significance of the association?
Some Distinctly Odd Fraudulent Paintings
Joseph Barabe — Barabe & Associates LLC
One problem faced by the forger of paintings is creating the illusion of age. In a recent case, were asked to examine a painting with some odd characteristics, with special attention to the signature of the artist. The painting was somewhat odd; it fluoresced strongly with UVA illumination, and the surface had a somewhat granular appearance when viewed with the stereomicroscope. In the course of the analysis, the hard work of the forger became his/her stumbling block, and with a bit more attention to pigment history, they could have succeeded in their deception. This forgery included some time-worn tricks and one never-before-seen trick by this analyst.
In another case, we were asked to examine five works in a large collection of paintings. Although each was allegedly made by different artists, they shared a number of suspicious characteristics. As all were (again, allegedly) originally gifts to the seller and were accompanied by letters supporting that status, the documents also were carefully examined and were found to share a number of incriminating characteristics.
WEDNESDAY AFTERNOON
Genuine or Replica? Authenticating Leeuwenhoek Microscopes — Video Presentation
Brian J. Ford
In the 1600s, Antony van Leeuwenhoek was the first person to use microscopes to study microbes. As a schoolboy I was recommended to search for previously unknown examples of Leeuwenhoek microscopes. I never anticipated that his original specimens had survived or that it would fall to me to discover them. Since his microscopes had been so comprehensively documented after his death, and the few surviving examples had been so comprehensively studied, it seemed impossible that more could come to light. Yet four more have since emerged, two of them within the space of a single year. Three of these unique instruments have passed through my hands, and two of them (one made of brass, the other of silver) were made available for a unique program of investigation in England at Cambridge University: scanning electron microscopy. This has revealed how Leeuwenhoek worked and has allowed me to develop a unique protocol for authenticating ancient scientific instruments.
Surgery and Foreign Matter: The Role of Microanalysis in Identification and Source Determination
Christopher S. Palenik — Microtrace LLC
Over the past 30-plus years, Microtrace has investigated numerous cases involving foreign matter and suspected foreign matter recovered from the human body during surgery. These have included foreign matter from eyes, posteriors, abdomens, gastrointestinal tracts, and lungs, among other parts of the body. The recovered substances have included 1) surgical materials that were unintentionally left in a patient during surgery, 2) contamination introduced with surgical devices or the surgical environment, 3) unintentionally ingested materials or respired particles that required surgical removal, and 4) fistulas that have let undigested substances into incompatible areas of the body. Through examples from our casework, this presentation will discuss the role that microanalysis has played in identifying these often heavily degraded items. After identifying an item, there is typically a subsequent request to determine, or at least place constraints on, the source or point of origin of the identified material. We have approached this question through a formal forensic comparison, when potential source materials are available. In other instances, when source materials are not available, the characteristics determined by microanalysis can be used from the beginning to identify or constrain a source.
Forensic Analysis of Recrystallized Inorganic Oxidizing Salts Used in Pyrotechnic-Based Improvised Explosive Devices Using Light Microscopy and Micro-Raman Spectroscopy
Geraldine Monjardez (presenting author), Jared Estevanes, and Patrick Buzzini — Department of Forensic Science, College of Criminal Justice, Sam Houston State University, Huntsville, TX
This study aimed to evaluate the advantages and challenges of analyzing post-blast explosive residues from pyrotechnic pipe bombs using light microscopy and micro-Raman spectroscopy. Two simulated improvised explosive devices (IEDs) were constructed using common materials that might be found in authentic bombing scenarios and detonated using pyrotechnics as the main charge. A wet and dry swabbing technique was compared to determine the most efficient swabbing method of recovery for inorganic oxidizers in post-blast debris. Samples were recrystallized using a water recrystallization method followed by in situ analysis with micro-Raman spectroscopy directly throughout the glass slide to prevent analyte loss. While water recrystallization had effects on the resulting Raman spectra, such as peak intensity reduction, ultimately, the final salt identifications were not affected. The detection of several inorganic oxidizers post-blast included the identification of potassium perchlorate (KClO4), potassium nitrate (KNO3), and barium nitrate (Ba(NO3)2). The detection of KNO3 using microscopy alone was more challenging due to its relatively low abundance compared to KClO4 but was aided with micro-Raman spectroscopy. Additionally, mixtures of inorganic oxidizers within single crystals were also observed. Overall, inorganic oxidizing salts in a post-blast scenario were successfully detected using the combined approach of light microscopy and micro-Raman spectroscopy.
An Approach to Low Explosive Analysis: Pyrotechnic Powders with Microscopical Emphasis
Wayne Moorehead — forensic TRACE
This presentation includes an analytical approach for analyzing intact low explosive powders. Compositional knowledge of propellant and pyrotechnic powders assists in the rapid analysis of an unknown. The scheme includes a flame ignition test, microscopical means (stereomicroscope, polarized light microscope with associated techniques, Fourier-transform infrared spectroscopy (FTIR), spectrometer optical bench and microscope, and scanning electron microscope using energy dispersive X-ray spectrometer), in addition to solubility and chemical color tests. Of the 2,128 recovered intact devices reported in 2018, approximately 31% were low explosive powders and were used in approximately 51% of the main explosive charge in post blast explosive devices (total of 228 reported for 2018). Select low explosive powders will be used for illustration of this analytical approach.
Development of Microscopical Methods for the Systematic Analysis of Chemically Reacted, Improvised Low Explosives, and Related Residues — Project Update III, the (Likely) Final Installment
Meggan King Dempsey — McCrone Research Institute
In January of 2020, McCrone Research Institute began a research project to use a microscopical approach to investigate the particles and residues resulting from a controlled burning and ashing of low explosives and related materials. One goal is to improve the comparison and analysis of unreacted, chemically reacted, and post-blast-related residues and increase the overall understanding of the process and mechanism that may result in the inability to obtain analytical results from evidence. Careful laboratory techniques have improved the success of historically challenging microchemical tests, and useful spot tests have also been identified. There have been two notable accomplishments: the development of an atlas with detailed photomicrographs and a detailed low-explosives characterization table. This presentation will discuss what has been accomplished, where this work fits in with current methodologies, and what the final product(s) may look like.
This project was supported by Award No. NIJ-2019-DU-BX-0047, awarded by the National Institute of Justice, Office of Justice Programs, U.S. Department of Justice.
Using the OSAC/ASTM Standard Guide for the Forensic Analysis of Explosives by Polarized Light Microscopy
William A. Randle — Missouri State Highway Patrol Crime Laboratory
The Ignitable Liquids, Explosives, and Gunshot Residue subcommittee of the Organization of Scientific Area Committees for Forensic Science (OSAC) began work on a standard guide for the analysis of explosives using polarized light microscopy in April 2017. A final version was placed on the OSAC Registry in April 2023, titled OSAC 2022-S-0023 Standard Guide for the Forensic Analysis of Explosives by Polarized Light Microscopy. The document underwent balloting at ASTM in December 2023. This presentation will discuss the application of this document to the analysis of explosives in conjunction with ASTM E3253 Practice for Establishing an Examination Scheme for Intact Explosives and E3329 Practice for Establishing an Examination Scheme for Explosive Residues.