Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Lactose intolerant bacteria
Name: Carolyn McPherson
Age: N/A
Location: N/A
Country: N/A
Date: N/A 

A student scientist is looking for a method to induce lactose intolerance in E. coli bacteria. Is there a suggestion for a method?

The prevailing wisdom among geneticists is that we cannot really "induce" lactose intolerance so much a we can "select" or "screen" for mutant bacteria that have become lactose intolerant. The idea is that mutations in particular genes do not occur as a response to some evolutionary or selective pressure; rather, mutations just happen randomly, and those that confer a growth advantage (in a particular situation) will help the bacterium grow faster than its siblings. In a previous session, I suggested one way to identify those bacteria; to induce mutations, any of several mutation-causing agents might be tried, including chemicals and UV light. In fact, one worthwhile experiment might be to see how various exposure to UV light might yield increasing numbers of lactose-intolerant mutants. For more details or discussion, you might write me directly (S. Triezenberg).

Click here to return to the Biology Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (, or at Argonne's Educational Programs

Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory