How to Prepare 10 Neutral Buffered Formalin
Preparing 10 neutral buffered formalin is a crucial step in various biological and medical applications, including preserving tissue samples for analysis and research. Neutral buffered formalin, also known as 10% NBF, is a fixative solution that helps to preserve the structure and integrity of biological tissues. This article will guide you through the process of preparing 10 neutral buffered formalin, ensuring that you have a reliable and effective fixative for your experiments.
Materials Needed
Before you begin preparing 10 neutral buffered formalin, gather the following materials:
– Formalin (37-40% formaldehyde solution)
– Distilled water
– Sodium carbonate (Na2CO3)
– Measuring cylinder
– Beaker
– Stirring rod
– Safety equipment (gloves, lab coat, and safety goggles)
Step-by-Step Instructions
1.
Calculate the amount of formalin and sodium carbonate needed
To prepare 10 neutral buffered formalin, you will need 10 parts of formalin and 1 part of sodium carbonate by weight. For example, to prepare 1 liter of 10 neutral buffered formalin, you will need 900 grams of formalin and 90 grams of sodium carbonate.
2.
Measure the formalin and sodium carbonate
Using a measuring cylinder, measure out the required amount of formalin and sodium carbonate. Be precise in your measurements to ensure the correct concentration of the final solution.
3.
Add the formalin to the beaker
Pour the measured formalin into a clean beaker. Ensure that the beaker is large enough to accommodate the solution without spilling.
4.
Add the sodium carbonate to the formalin
Slowly add the sodium carbonate to the formalin while stirring continuously. It is essential to add the sodium carbonate gradually to prevent the formation of lumps or bubbles.
5.
Stir the solution
Stir the solution thoroughly until the sodium carbonate has completely dissolved. This process may take a few minutes, so be patient and ensure that the solution is well-mixed.
6.
Add distilled water
Once the sodium carbonate has dissolved, slowly add distilled water to the beaker. Continue stirring the solution as you add the water. The total volume of the solution should now be 1 liter.
7.
Adjust the pH
The pH of the 10 neutral buffered formalin should be between 7.2 and 7.4. To adjust the pH, you can add a small amount of 1M hydrochloric acid or sodium hydroxide solution. Test the pH using a pH meter or pH indicator strips, and make adjustments as needed.
8.
Stir the solution again
After adjusting the pH, stir the solution thoroughly to ensure that all the ingredients are well-mixed.
9.
Label the container
Once the 10 neutral buffered formalin is prepared, label the container with the date, concentration, and any other relevant information.
10.
Store the solution properly
Store the 10 neutral buffered formalin in a cool, dry place away from direct sunlight. Keep the container tightly sealed to prevent evaporation and contamination.
By following these steps, you can successfully prepare 10 neutral buffered formalin for your biological and medical applications. Always prioritize safety and accuracy in your preparation process to ensure reliable and effective results.
