· Parts and Uses - use diagram (refer to appendix)
· Care and Maintenance
o How to carry a microscope
o How to clean a microscope
o How to store a microscope
· How to Focus?
Visually line the slide up with the lens.
Focus on low power.
Move slide so object is in the center of the field of vision.
Refocus on medium power using fine adjustment.
Again, make sure the object is in the center of the field of vision.
Refocus on high power using fine adjustment ONLY!
· Fibers are commonly found with burglary,
assault, breaking and entering, hit and run accidents, etc.
· Fibers can come from clothes, carpet, curtains, wigs, furniture,
· Natural Fibers - produced entirely from plants or animals
Sheep - wool
Goats - mohair & cashmere
Plant fibers - cotton
· Man-Made Fibers
Regenerated Fibers - produced using natural raw
materials ( ex. - rayon)
Synthetic Fibers - produced using synthetic chemicals (ex. - nylon
· Identification Using Fibers
"Fit together" like puzzle pieces when
fabric is torn - conclusive evidence
Microscopic comparison - color, diameter, striations
Color comparison of specific dyes used with micro-spectrophotometer
Chemical composition - make sure fibers are from the same generic
class and subclass (if possible) with infrared spectrophotometry
· Collecting and Handling Fibers
Clothes are placed in paper bags with each
article going into a separate bag.
Carpets and bedding should be folded and placed in a paper bag to
protect the areas that may contain fibers.
Fibers may be removed form an object by using clean tweezers and a
folded piece of paper that is labeled with the location of the sample,
date, time, and name of investigator.
Most objects will be examined in the lab to find fiber evidence; fibers
are usually not examined at the crime scene.