Plant Physiology (Biology 327)  - Dr. Stephen G. Saupe;  College of St. Benedict/ St. John's University;  Biology Department; Collegeville, MN  56321; (320) 363 - 2782; (320) 363 - 3202, fax;    ssaupe@csbsju.edu

Question(s): Do protoplasts respond to the osmolality of the medium? What is the effect of adding detergent to the protoplasts?

Hypotheses: Protoplasts will shrink when treated with a saline solution (hypertonic medium) and expand/explode when placed in water (hypotonic medium). Detergent will destroy the protoplast (by dissolving the membrane).

Protocol:

1. Place a drop of the red cabbage protoplast suspension and a few grains of salt on a depression slide. Observe the response of the protoplasts. Describe and sketch (or photograph) the results of treating the protoplast suspension with salt. Include a caption and plate magnification. 
   
2. Place a drop of water and a drop of protoplast suspension on another depression slide. Describe and sketch (or photograph) the results.
   
3. Repeat with a drop of detergent (1% Tween20).
   

Data, Analysis & Conclusions: 

1. Do our results of treating the protoplasts with salt support our predictions?  Offer an explanation for your observations.
   
2. Do our results of treating the protoplasts with water support our predictions?  Offer an explanation for your observations.
   
3. Do our results of treating the protoplasts with detergent support our predictions?  Offer an explanation for your observations.

Last updated:  01/07/2009     � Copyright  by SG Saupe