There are several ways to increase the pH of peptone water: 1. Add a base: To increase the pH of peptone water, you can add a base such as sodium hydroxide (NaOH) or potassium hydroxide (KOH). You will need to use a pH meter or pH strips to determine the amount of base to add in order to achieve the desired pH. 2. Use a buffer: A buffer is a substance that can resist changes in pH. You can use a buffer solution to increase the pH of peptone water by adding a small amount of the buffer to the solution. 3. Use a pH adjuster: There are several commercial products available that are specifically designed to adjust the pH of solutions. These products can be added to peptone water to increase the pH. It is important to note that the pH of peptone water can also be increased by adding other substances that are basic in nature, such as bicarbonate or carbonate ions. However, it is generally recommended to use a pH meter or pH strips to accurately measure the pH of the solution and ensure that the desired pH is achieved.