Basic HTML Version
SOP8 – Live Organisms 10-50 μm
60
Lugol’s solution for phytoplankton preservation:
Material
Amount
Notes
DI water
450 mL
Potassium Iodide
50 g
Glacial Ascetic Acid
50 mL
Add last
This solution will keep for 6 months.
1 mL of formalin should be added to samples that will be
stored for any length of time.
9.3. Preparation of Working Stocks
Working stocks are prepared beforehand and stored in
-10°C freezer. Mark current working
stock with the date of first use and a dot on top of the vial.
9.3.1. Cell Tracker Green - CMFDA (5-chloromethylfluorescein diacetate)
1.
Completely thaw a 50 µg vial of CMFDA (special packaging option from Invitrogen).
2.
Working stock: Add 430 µL of DMSO to vial and vortex to mix (250 µM).
3.
Divide the working stock into 100 µL aliquots and store at -10ºC.
4.
Add 10 µL of working stock to 990 µL of sample for a final CMFDA concentration
of 2.5 µM.
9.3.2. Fluorescein diacetate – FDA
1.
Primary stock: Add 5 mL of DMSO to 100 mg of dry FDA and vortex to mix (50
mM).
2.
Working stock: Add 980 µL of DMSO to 20 µL of primary stock (1 mM).
3.
Divide the working stock into 100 µL aliquots and store at -10ºC.
4.
Add 5 µL of working stock to 995 µL of sample for a final FDA concentration of 5
µM.
When not in use, keep the CMFDA & FDA probes in a -10°C freezer and shielded from light.