Department of Chemistry and Biochemistry Seminar Series

Event Details

Please join us this Friday for our CHEM 280/180H seminar presentation with John Gutierrez. See the information below and attached flyer for additional details.

Speaker:         John Gutierrez, senior biochemistry major.

Title:               Magnifying the Truth: A Look Into TEM and SEM in Forensic Science

Date:              Friday, October 6, 2023

Time:              Noon – 12:50 p.m.

Location:         Ag Mechanics, Room 102


Forensic science applies the scientific method to the examination of evidence collected at a crime

In terms of evidence, this can range from being macroscopic, like a shoe mark impression, to
microscopic like a pollen grain or skin cell.

To analyze evidence, various analytical techniques and
scientific tools, such as gas chromatography, are used to analyze ingested drugs or alcohol before death, or PCR is used to amplify a small amount of DNA collected at a crime scene.

Interestingly, microscopy can also be used to analyze different forms of evidence by magnification.

Conventional light microscopes provide good magnification and resolution for various evidence, but more recently, electron microscopes are being used to provide high levels of magnification and resolution that are incomparable in forensic analysis.

Two common electron microscopes are transmission electron microscopes (TEM) and scanning electron
microscopes (SEM). TEM provides higher magnification and resolution when compared to SEM, however, the sample needs to be 200 nm or less in thickness, therefore sample preparation can be

On the other hand, SEM observes the surface morphology of the sample and can, therefore, be used to analyze much thicker samples than TEM, however, the cost is reduced magnification.

This talk will discuss the applications of TEM and SEM in forensic science to see how each provides crucial information about the evidence.

Click the link below to see the seminar’s flyer.