IIT-McCrone Forensic Chemistry Microscopy Laboratory (CHEM 476)
LAB OUTLINE & SYLLABUS
Course schedule: 2:00 p.m. – 8:00 p.m. Wednesdays. Location: McCrone Research Institute, Chicago.
Students will acquire the basic knowledge and practical skills to apply forensic polarized light microscopy methods to common physical trace including fibers, glass, hair, explosives, minerals, drugs, etc.
- Perform reliable operations and techniques with the polarized light microscope (PLM)
- Identify small particles, including organic and inorganic chemical compounds
- Characterize fibers from animal, mineral, vegetable, and man-made origins
- Perform microchemical and microcrystal tests
- Practice visual thermal/fusion methods
- Study crystals and optical crystallography
Lectures and laboratory demonstrations using video for macro- and micro-projection will cover PLM theory, techniques, and interpretation. Each student will perform applicable exercises on the polarized light microscope.
Week 1 • Physical optics: reflection, refraction, refractive index, dispersion, lenses, aberrations, objectives, oculars, and condensers• Image formation, illumination, resolving power, contrast • MicrometryReading assignment: Appendix 2 & 6, Polarized Light Microscopy textbook 1-41, 95-142
Week 2 - Quiz #1 (25pts) • Crystal morphology, crystallization• Measuring refractive index, Becke line test• Crystal optics: color and pleochroismReading assignment: Appendix 8, Polarized Light Microscopy textbook 142-149 Week 3• Crystal optics continued• Crossed polars: birefringence, retardation, extinctionReading assignment: Appendix 10
Week 4 - Quiz #2 (25pts) • Sign of elongation• Characterization and identification of knowns and unknowns• Identification of small single particles: synthetic and natural fibers, diverse biological particles, minerals, and other productsReading assignment: Appendix 12, Polarized Light Microscopy textbook 150-168, 206-210. Please think of review questions for next week. Week 5• Conoscopy• Microchemistry for cations, anions, etc., and microcrystal tests for Illicit drugs• Visual thermal analysis (i.e. fusion methods)• Particle-picking, manipulation (time permitting)Review questions
Week 6 – Final microscopy exam (350 pts)• Comprehensive examination
Week 1 • Physical optics: reflection, refraction, refractive index, dispersion, lenses, aberrations, objectives, oculars, and condensers• Image formation, illumination, resolving power, contrast • MicrometryReading assignment: Appendix 2 & 6, Polarized Light Microscopy textbook 1-41, 95-142
Week 2 - Quiz #1 (25pts) • Crystal morphology, crystallization• Measuring refractive index, Becke line test• Crystal optics: color and pleochroismReading assignment: Appendix 8, Polarized Light Microscopy textbook 142-149 Week 3• Crystal optics continued• Crossed polars: birefringence, retardation, extinctionReading assignment: Appendix 10
Week 4 - Quiz #2 (25pts) • Sign of elongation• Characterization and identification of knowns and unknowns• Identification of small single particles: synthetic and natural fibers, diverse biological particles, minerals, and other productsReading assignment: Appendix 12, Polarized Light Microscopy textbook 150-168, 206-210. Please think of review questions for next week. Week 5• Conoscopy• Microchemistry for cations, anions, etc., and microcrystal tests for Illicit drugs• Visual thermal analysis (i.e. fusion methods)• Particle-picking, manipulation (time permitting)Review questions
Week 6 – Final microscopy exam (350 pts)• Comprehensive examination