Lecane
- Lecane hamata
- Lecane luna
- Lecane quadridentata
[ref. ID; 6861]
Test system
Fluorometric assay based on inhibition of activity of the enzyme Phospholipases A2 (PLA2)
Strains
Neonates 24 hr old. (500 parthenogenetic eggs in 1-ml well with U.S.EPA medium at pH 7.5. The eggs were incubated at 16:8 hr light:dark, at 25 degrees C. Hatching efficiency (24 hr) was always >37% under these conditions.
Toxicants
Organic solvents (benzene, ethyl acetate, toluene, vinyl acetate), metals (cadmium, copper, chromium, lead, mercuric cloride, titanium).
Test design
30 animals (neonates were exposed to fluorogenic substrate 2-[6-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-amino]-hexanoyl-1-hexadecanoyl-sn-glycero-3-phopsphocholine) were placed in the each well of a polystyrene 24-well plate, in the dark at 25 degrees C. Exposure period 30 min. After the exposure period, 1 ul of the enzyme substrate (17.2 uM per well) was added to each well, and the plate was gently shaken. The plate was then incubated in darkness at 25 degrees C for 15 min. After incubation with the substrate, we added 25 ul of 10% formalin solution (200 uM per well) to kill the rotifers and stop enzymatic activity.
Measurements
Intensity of fluorescence.
Evaluations
EC50, NOEC, LOEC.
[ref. ID; 7164]
Test system
In vivo esterase inhibition test
Strains
Neonates less than 24 hr old.
Toxicants
Benzene, Ethyl acetate, Toluene, Vinyl acetate. Atomic absorption standards (cadmium, copper, chronium, lead, titanium), Mercuric chloride.
Test design
The protocol of Burbank and Snell (1994).
Each test was begun by adding 750 ul of U.S.EPA medium (negative control) or each toxicant concentration diluted with U.S.EPA medium into each well of a polystyrene 24-well plate (Corning, NY, USA). Then 30 animals were transferred. Rotifers were exposed in the dark at 25 degrees C for 30 min. After exposure, 2 ul of cFDAam were added to each well and the plate was gently shaken, and then incubated in the dark at 25 degrees C for 15 min. After incubation, 25 ul of 10% formalin solution (200 uM per well) were added to kill the rotifers, stopping the enzymatic activity.
Measurements/observations
Intensity of fluorescence in the gut.
Evaluations
EC50, NOEC, LOEC.
[ref. ID; 6861]
Test system
Fluorometric assay based on inhibition of activity of the enzyme Phospholipases A2 (PLA2)
Strains
Neonates 24 hr old. (500 parthenogenetic eggs in 1-ml well with U.S.EPA medium at pH 7.5. The eggs were incubated at 16:8 hr light:dark, at 25 degrees C. Hatching efficiency (24 hr) was always >37% under these conditions.
Toxicants
Organic solvents (benzene, ethyl acetate, toluene, vinyl acetate), metals (cadmium, copper, chromium, lead, mercuric cloride, titanium).
Test design
30 animals (neonates were exposed to fluorogenic substrate 2-[6-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-amino]-hexanoyl-1-hexadecanoyl-sn-glycero-3-phopsphocholine) were placed in the each well of a polystyrene 24-well plate, in the dark at 25 degrees C. Exposure period 30 min. After the exposure period, 1 ul of the enzyme substrate (17.2 uM per well) was added to each well, and the plate was gently shaken. The plate was then incubated in darkness at 25 degrees C for 15 min. After incubation with the substrate, we added 25 ul of 10% formalin solution (200 uM per well) to kill the rotifers and stop enzymatic activity.
Measurements
Intensity of fluorescence.
Evaluations
EC50, NOEC, LOEC.
[ref. ID; 7164]
Test system
In vivo esterase inhibition test
Strains
Neonates less than 24 hr old.
Toxicants
Benzene, Ethyl acetate, Toluene, Vinyl acetate. Atomic absorption standards (cadmium, copper, chronium, lead, titanium), Mercuric chloride.
Test design
The protocol of Burbank and Snell (1994).
Each test was begun by adding 750 ul of U.S.EPA medium (negative control) or each toxicant concentration diluted with U.S.EPA medium into each well of a polystyrene 24-well plate (Corning, NY, USA). Then 30 animals were transferred. Rotifers were exposed in the dark at 25 degrees C for 30 min. After exposure, 2 ul of cFDAam were added to each well and the plate was gently shaken, and then incubated in the dark at 25 degrees C for 15 min. After incubation, 25 ul of 10% formalin solution (200 uM per well) were added to kill the rotifers, stopping the enzymatic activity.
Measurements/observations
Intensity of fluorescence in the gut.
Evaluations
EC50, NOEC, LOEC.
[ref. ID; 6861]
Test system
Fluorometric assay based on inhibition of activity of the enzyme Phospholipases A2 (PLA2)
Strains
Neonates 24 hr old. (500 parthenogenetic eggs in 1-ml well with U.S.EPA medium at pH 7.5. The eggs were incubated at 16:8 hr light:dark, at 25 degrees C. Hatching efficiency (24 hr) was always >37% under these conditions.
Toxicants
Organic solvents (benzene, ethyl acetate, toluene, vinyl acetate), metals (cadmium, copper, chromium, lead, mercuric cloride, titanium).
Test design
30 animals (neonates were exposed to fluorogenic substrate 2-[6-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-amino]-hexanoyl-1-hexadecanoyl-sn-glycero-3-phopsphocholine) were placed in the each well of a polystyrene 24-well plate, in the dark at 25 degrees C. Exposure period 30 min. After the exposure period, 1 ul of the enzyme substrate (17.2 uM per well) was added to each well, and the plate was gently shaken. The plate was then incubated in darkness at 25 degrees C for 15 min. After incubation with the substrate, we added 25 ul of 10% formalin solution (200 uM per well) to kill the rotifers and stop enzymatic activity.
Measurements
Intensity of fluorescence.
Evaluations
EC50, NOEC, LOEC.
[ref. ID; 7164]
Test system
In vivo esterase inhibition test
Strains
Neonates less than 24 hr old.
Toxicants
Benzene, Ethyl acetate, Toluene, Vinyl acetate. Atomic absorption standards (cadmium, copper, chronium, lead, titanium), Mercuric chloride.
Test design
The protocol of Burbank and Snell (1994).
Each test was begun by adding 750 ul of U.S.EPA medium (negative control) or each toxicant concentration diluted with U.S.EPA medium into each well of a polystyrene 24-well plate (Corning, NY, USA). Then 30 animals were transferred. Rotifers were exposed in the dark at 25 degrees C for 30 min. After exposure, 2 ul of cFDAam were added to each well and the plate was gently shaken, and then incubated in the dark at 25 degrees C for 15 min. After incubation, 25 ul of 10% formalin solution (200 uM per well) were added to kill the rotifers, stopping the enzymatic activity.
Measurements/observations
Intensity of fluorescence in the gut.
Evaluations
EC50, NOEC, LOEC.