DNA Forensics

DNA Forensics Lab Introduction
In this lesson, students will use their understanding and skills from the “Getting Started Series” to solve a mystery using restriction enzymes to create a DNA fingerprint. Forensic science can employ restriction enzymes – commonly described as molecular scissors– that cut DNA at specific sequences. The variation in DNA from one person to the next in certain parts of the genome are so great that the probability of two people sharing the same DNA fingerprint pattern is essentially zero.
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    After introducing the mystery at hand, students will perform a restriction digest, and then use gel electrophoresis to separate the resulting DNA fragments by size. Based on the results from their experiment, students make a conclusion citing their evidence – and perhaps suggest an answer to “Who done it?”

    Similar techniques are applied to diverse areas of science. This approach can be used to investigate remains in an archeological site or to determine ancestry. Forensic science techniques are also commonly used in criminal, civil, public health, botany, anthropology, and conservation investigations.

Lesson Resources
Student Guide – Download and edit student worksheets to be completed during the DNA Forensics Lab.
Lesson Slides – Articulates with the student guide above and accompanying lesson plans below.
Lesson Plan – Suggested times for pacing, sequence and activities for the lab. Includes vocabulary tool, background information, etc.

Lab Resources
Student Lab Protocol – Students follow these instructions when doing the DNA Forensics Lab.
Preparing the Classroom for the Lab – How to set up group stations for this lab experience.
Inventory Guide – Reagents and materials checklist for one classroom kit. Includes equipment and classroom needs for the lab.

– Students will use evidence from their
experiments to support their stated claim
– Students can describe how restriction
enzymes can be used to differentiate
between variations in the sequence of
human DNA (and other organisms)
– Core skills in molecular biology including
micropipetting and gel electrophoresis
are appropriately applied by students
during their investigations

Disciplinary Core Ideas:
LS3.A – Inheritance of Traits
“…not all DNA codes for a protein…” The regions the restriction enzymes cut vary among individuals and typically do not code for a protein

LS3.B – Inheritance of Traits
“…distribution of traits on genetic and environmental factors”

Science and Engineering Practices:
– Planning and Carrying out Investigations
– Analyzing and Intercepting Data Patterns

Familiarity with the following biology concepts may be helpful for students prior to using the lesson resources.
– Getting Started Series Parts 1-3 from
BABEC to learn about DNA extraction,
Micropipetting, and gel electrophoresis
– Variation in DNA sequence (order of
bases) exists among humans and other

Kitty MeiDNA Forensics