Sedi-Lab™ Testing Educational Kit
Determining acute toxicity in sediments, soils,
and solid wastes for the classroom
Timeline: 150 Minutes to 225 Minutes
About the Sedi-LabTM: The Sedi-LabTM determines the acute toxicity in sediments, suspended sediments, soils, and solid wastes. The Sedi-LabTM detects toxicity directly without labour intensive solvent extraction procedures. It will pick up additive, synergistic, and antagonistic effects from toxicant mixtures. |
Reaction: The Sedi-Lab™ kit’s assay is based on the ability of a toxicant to inhibit the de novo synthesis of an inducible enzyme (β-galactosidase) in a highly permeable mutant of E. coli and the results manifest as an easily observable colour change after a short incubation period. Sensitivity and performance of the test is enhanced by exposing the bacteria to stressing conditions prior to lyophilization, after which they are rehydrated in a cocktail containing a specific inducer of β-galactosidase and essential factors required for recovery of the bacteria from their stressed condition. The activity of the induced enzyme is detected by hydrolysis of a chromogenic substrate to produce a clearly visible blue or yellow colour change. Toxic materials that interfere with the recovery process will decrease enzymatic synthesis and inhibit colour production once the chromogen is added. Comparing the amount of colour produced between a test sample and a reference soil provides a measure of toxic potency. |
EDUCATIONAL LAB HANDOUT
Download the Handout which includes Educator Resources, Student Handout, Preparation, and Lab Procedure |
Learning Goals (see About Us for Details): LG 1, LG 2, LG 3, LG 4, LG 7, LG 10 Sedi-LabTM Information for the Educator The Sedi-LabTM is offered in a format that will meet the needs of most class sizes and schedules. |