Answer to Question #110719 in Molecular Biology for FRIDAY

Question

Question 11: The PBS protocol above says to adjust pH to 7.4 with HCl. What does this imply on the pH of 10x PBS before adjusting the pH, would it be greater or smaller than 7.4?

Answer 1

pH scale indicates the acidity and alkalinity of a solution. pH is used to show if the solution is acidic or basic and reflects the concentration of H+ ion. pH scale values lie between 0 and 14. pH<7 means acidic solution and pH>7 reflects basic solution. HCl is an acid. As a result, it is added to the PBS solution to lower pH. Adding HCl decreases pH increasing the concentration of H+ ions and neutralising OH- ions. Therefore, the pH of 10x PBS before its adjusting was higher greater than 7.4.