LD50 of salt solution on Mung beans Serial Dilutions LD50 of salt solution on Mung beans

Cut piece of paper towel and insert into bag Get 2 x 3 inch jewelry bags jewelry supply store.  See product # 52-002 on second table @ http://www.aajewelry.com/templates/product_list_dropdown_pix.aspx?GroupGuid=5523  Cut piece of paper towel and insert into bag Staple across the bag such that there is space for roots to grow Add 10 to 15 seeds to each bag

Make a 0.2-g/mL NaCl STOCK solution - Measure 2 grams of salt on balance. Get 10ml of water in a graduated cylinder. Add 2 g of sodium chloride and add water to 10 mL to beaker… this is your stock solution. 0.2 g/mL NaCl Stock Solution

Decide how many different concentrations you want to do. Don’t forget a control. You will need one seed bag for each concentration. You will need one test tube for each concentration. Get the materials you need.

Add 5 mL of tap water to each of you test tubes

Add 5 mL of Stock Solution to first test tube using graduated cylinder.

Mix the first Tube

Take 5 mL of first tube and add to second tube

Mix

Repeat until last test tube.

Repeat until last test tube.

Remove 5 ml from your last test tube All test tubes should have 5 ml

Stock Solution

Squeeze bulb fully, it will not totally fill up that is okay. Pipet has a 5ml capacity but we only need 3 ml.

Write: Stock Solution .2 g/l on bag

Water

Water Write: Control 0 g/l on bag

0.1 g/mL Solution

0.05 g/mL Solution

Etc.

Put all the bags upright in the beaker that had the stock solution. Put in dark area for one about one week Determine the percent dead for each concentration. Graph with the % dead on the y-axis and concentration on the x-axis. Determine the LD50 or the concentration where 50% of the seeds did not germinate

Percentage of population killed by a given dose 100 75 50 25 2 4 6 8 10 12 14 16 Percentage of population killed by a given dose Dose (hypothetical units) LD