Bioassay is a type of scientific experiment used in the development of new drugs and monitoring pollutants. It estimates the potency of a substance, by testing its effect on living matter. In other words, it determines how much of the substance is needed to poison an individual, without testing it on any humans or animals. From here the TC50 of the substance can be adjusted for dealing with humans and animals over plants.
In this lab we attempted to find the potency of sodium chloride by testing it on radish seeds. The lab seeks to determine the potency of NaCl by determining its effect in different concentrations on the growth of the seed roots. This served to give us a cheap and quick way to experience a bioassay experiment from our classroom.
Hypothesis
I believe that a greater concentration of NaCl will correlate with a lower seed germination rate, as well as a shorter radicle length.
Procedure
1. Label petri dishes with the appropriate concentration levels and place filter paper in each dish.
2. Treat each dish with 2mL of the appropriate concentration of the bleach solution
3. Place 6 seeds in each dish. Make sure they do not touch the sides of the dish or each other.
4. Leave the dish in a dark place so that the roots can grow.
5. Dishes were left in the dark for four days due to the blizzard.
6. Recover dishes and measure the length of the roots at different concentrations
7. Calculate the averages of the roots and number of germinated seeds with those of the different groups
8. Create graphs for both the root length and number of germinated seeds
Results length of radicle (mm) Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Average
% NaCl M NaCl
100.0 0.200 8.4 20.2 41.4 18.2 11.8 20.4 20.1
50.0 0.100 31.2 66.0 72.0 34.2 32.4 6.6 40.4
37.5 0.075 32.0 67.4 81..8 42.2 45.0 11.2 39.6
25.0 0.050 45.2 69.6 91.8 39.8 39.4 29.2 52.5