Twenty four and forty hour brine shrimp toxicity test:
The 24 h brine shrimp toxicity test has been used for more than 20 years for the assessment of the cytotoxicity of plant materials .
Replicate samples of the aqueous seed extract were prepared at a concentration
of 1 mg/mL in 3% NaCl, pH 8. A green tea infusion was prepared in the same manner to serve as a well known food control.
Brine shrimp (Artemia salina) eggs were hatched in salt water (3% NaCl) and nauplii were transferred to vials containing 15 mL of test solution.
These were incubated for 24 h at room temperature. Following incubation, the numbers of active nauplii were counted and mean percent survival calculated for both
samples, with corresponding standard deviations.
Additional incubation to 40 h was also carried out to determine the effect of longer exposure times. The concentration resulting in lethality to 50% of the nauplii (LC50) was determined from survival rates. In this test, aswell as in the reverse mutation and primary DNA damage tests, comparisons were made with Student’s t-test.