brine shrimp lethality assay

Summary

This video provides a comprehensive guide to conducting a brine shrimp cytotoxicity bioassay experiment. Students will culture brine shrimp, evaluate the toxicity of various substances, and analyze the results. The procedure includes preparing artificial seawater, hatching brine shrimp, preparing sample extracts (e.g., herbal plants or consumer products), and conducting a 24-hour observation period. Data collection involves counting the number of live nauplii in sample and control cups, calculating survival percentages, and graphing the results. The experiment aims to help students understand the effects of different substances on marine life and improve their laboratory analysis skills.

Takeaways

• 😀 Brine shrimp bioassay evaluates the cytotoxicity effects of various substances or extracts on brine shrimp survival.
• 😀 The necessary materials include brine shrimp eggs, plastic cups, syringes, salt, distilled water, and magnifiers, along with the selected samples for testing.
• 😀 The brine shrimp eggs must be kept in the refrigerator if not used immediately.
• 😀 Samples for toxicity testing can include herbal extracts, food or beverage products, and personal care items like cologne or sanitizers.
• 😀 Solid samples must be fully dissolved in water, while liquid samples should be non-viscous and transparent for optimal shrimp movement.
• 😀 When preparing herbal extracts, ensure you are familiar with the plant, and wear gloves and an apron during the process.
• 😀 Dilute concentrated samples to a 1:10 ratio (1 part sample, 9 parts water or solvent) for proper testing.
• 😀 Each group member will test different concentrations or brands of the same sample, with duplicate test cups for each setup.
• 😀 Control cups (without samples) are essential to observe the baseline mortality rate of shrimp, confirming whether any mortality is due to the sample or starvation.
• 😀 Mortality data should be recorded at regular intervals (every 6 hours for 24 hours), and calculations for the percentage of live nauplii should be based on control groups.

Q & A

What is the primary goal of the brine shrimp bioassay activity?

The primary goal of the brine shrimp bioassay is to evaluate the cytotoxicity effects of specific substances or extracts and report the results and analyses.

What materials are required for the brine shrimp bioassay experiment?

The materials required include 8 oz plastic transparent cups, 2 spoons or stirrers, 2 1 ml syringes, 6 30 ml sauce cups, 1 20 ml measuring cup, 1 vial of brine shrimp eggs, non-iodized salt, distilled water, a magnifying glass, and samples for testing.

Why should brine shrimp eggs be stored in the refrigerator?

Brine shrimp eggs must be kept in the refrigerator if not used immediately to preserve their viability and ensure they hatch properly when needed.

What types of samples can be tested for toxicity in this experiment?

The samples can include herbal plants, food or beverage products, cologne, sanitizers, or any other substances with known medicinal properties or those used by humans or animals. These can be in solid, liquid, extract, or tincture form.

How should solid samples be prepared for the brine shrimp bioassay?

Solid samples must be completely dissolved in water before testing them with the brine shrimp, ensuring the samples are non-viscous to allow for shrimp movement.

How do you prepare an extract from a plant for testing?

To prepare an extract, wash the leaves thoroughly, cut them into small pieces, grind them with a mortar and pestle while adding water or alcohol for tinctures, and filter the resulting mixture. Alternatively, a blender or food processor can be used.

Why is dilution necessary in this experiment?

Dilution is necessary to adjust the concentration of the sample so that it is within an effective range for testing. It also helps eliminate interferences from other substances in the sample that could skew the results.

What is the dilution ratio used in this experiment?

A 1:10 dilution ratio is used, meaning one drop of the sample is mixed with nine drops of water or solvent to prepare the test samples.

What should be done before transferring brine shrimp into the test cups?

Before transferring the brine shrimp, the artificial seawater should be prepared, and approximately 10 to 15 live brine shrimp should be transferred into each test cup using a 1 ml syringe.

How do you record the data during the experiment?

Data is recorded by counting the number of live shrimp in each test cup every six hours for 24 hours and noting the results in a table. The percentage of live shrimp is calculated by comparing the number of live shrimp in the sample cups with the number of live shrimp in the control cups.

What should be done if the number of shrimp in the sample cups is greater than in the control cups?

If the number of shrimp in the sample cups exceeds that in the control cups, this suggests the sample may be providing nutrients or inducing hatching, which would result in a percentage greater than 100.