Question

With a fresh transfer pipette, carefully draw \(0.6 \mathrm{~mL}\) of broth out of your sample without disturbing the pellet at the bottom, and transfer to a clean glass test tube. Label this tube with your name and "PW-Sample."

Short answer

Draw 0.6 mL of broth without disturbing the pellet and transfer it to a labeled test tube.

Step-by-step solution

Prepare the Pipette

Take a fresh, sterile transfer pipette and make sure it is ready for use. This may involve ensuring that the pipette is clean and undamaged.

Draw the Broth

Insert the pipette into the sample tube, carefully avoiding disturbing the pellet at the bottom. Gently draw exactly 0.6 mL of the broth into the pipette.

Transfer Broth

Gently transfer the drawn 0.6 mL of broth from the pipette into a clean glass test tube to avoid contamination.

Label the Tube

Label the clean glass test tube with your name and 'PW-Sample' for proper identification.

Key concepts

broth transfer

When performing a broth transfer, it's important to handle the sample delicately to avoid disturbing any sediments. Start by using a sterile pipette, inserting it gently into the sample, and drawing only the required volume of broth. In this process, ensure that you don't stir the mixture, as sediments may affect the purity of your sample. Broth transfers are fundamental in microbiological experiments where clear solutions are needed for accurate results.

sample labeling

Properly labeling your samples is crucial in laboratory settings. This practice avoids mix-ups and ensures every step of your research is traceable. Write clear, easily readable labels. Typically, include crucial information such as your name, the contents (e.g., 'PW-Sample'), and the date of the transfer. By keeping this information visible, you can readily identify your samples and maintain organized records.

sterile pipette use

Using a sterile pipette is essential to prevent contamination. Before starting, confirm that the pipette is clean and free from any visible damage. Sterility eliminates unwanted microorganisms or substances from entering your sample. Always avoid touching the pipette's tip to any surfaces. If you accidentally touch it, replace it with a new, sterile one. This care ensures the reliability and validity of your experimental results.

avoiding contamination

Contamination can significantly impact your experiment’s outcomes. Here are some tips to avoid it:

• Work in a clean environment and ensure all tools and surfaces are sterilized.
• Use new, sterile pipettes and avoid touching the tips.
• Cap your sample tubes immediately after transferring the broth.
• Label your samples accurately to avoid cross-contamination.

By following these practices, you create a more controlled experimental setup and obtain more reliable data.