Forensics: DNA Evidence

This is my DNA Evidence lecture given in a forensics class about types of evidence that contain DNA.  It also describes Polymerase Chain Reaction (PCR) and DNA Fingerprinting by electrophoresis in detail.  There is also an embedded youtube video in the prezi and the powerpoint.  The content in the prezi and powerpoint are identical so it is just a matter of choice for the teacher.  Do you want to use the free prezi or purchase the powerpoint from my TPT store?

Topics include:

  • DNA Structure
  • Polymerase Chain Reaction
  • Gel Electrophoresis
  • DNA Fingerprinting
  • Types of DNA Evidence

The prezi above is available for free and there is a student note-guide available in my TPT store, plus a powerpoint version of the prezi if you prefer that format:

DNA Evidence Student Note Guide to accompany a FREE prezi! DNA Evidence powerpoint presentation and student note guide

In Practice…

This lecture takes approximately 75 minutes depending on how much detail and examples are given.  It is good to use in a Forensics course in high school or introductory college level setting.  It includes a refresher section but most students  have had some introductory biology so they have been exposed to DNA structure and replication.

DNA Evidence Inspiration

Here are some of the best links to resources on DNA evidence:

Have you found a good resource about DNA evidence that should be part of this list? Add it in the comments so we can put it in the list too!

Biotechnology Lecture & Note Guide

BiotechCoverThis PowerPoint presentation and student note guide handout contains 29 slides introducing Biotechnology and an 11-page handout for students to fill in during the lecture. I have used it with Biology classes and Forensics classes. It includes the explanations of restriction enzymes, gel electrophoresis, PCR, recombinant DNA and transformation, genomics, and proteomics.
This presentation with class discussion would take 90 minutes or more in my classroom, depending on the depth of discussion. The student note guide is included as both an editable Word document and a PDF file. The powerpoint file is also editable!

Available through my TeachersPayTeachers store for a small fee:


DNA – The Secret of Photo 51

Photo 51The NOVA video The Secret of Photo 51 is a resource that I like to use near the beginning of our study of DNA when we are learning about the structure of DNA. It is a good introduction to the work that went on in discovering the structure of DNA and also gets into ‘What Scientists Do.’

Brief summary of the video:

The Secret of Photo 51 takes us into post-World War II Europe where the race to determine the structure of DNA was heating up. The video describes what Watson and Crick were doing, but focuses on their ‘unknowing collaborator’ Rosalind Franklin. She was using X-ray diffraction techniques to analyze the structure of DNA. It is said that without knowledge of her unpublished work Watson and Crick would not have been able to determine the structure of DNA.

In addition to discussing DNA structure, the following topics become good discussions with this video:

  • What scientists do – the fact that in science your success is measured by what you can publish in scientific journals, and funding for your work is provided based on both your past work and your ideas
  • How life has changed for women scientists – Rosalind Franklin was not treated well, or as an equal, by the men that she was working with at the time
  • Scientific press vs. popular press (in terms of Watson’s book)
  • The Nobel Prize – I like to describe it as winning the Superbowl of science!

The video is 1 hour long and is available through the PBS store or your library. For more information about the film visit the PBS website:

I have created a video guide with questions for students to fill in as they watch this film.  If you are interested in the handout it is available through my Teacher Pay Teachers store by clicking here: