There is no standard concentration for NaOH and H2SO4 when adjusting the pH of media for bacteria, but caution is advised with concentrations used. A common practice in some labs is to use a 5 M NaOH solution, especially when combined with a buffer like HEPES, as it allows for precise pH adjustments without significantly increasing the volume. If buffers are not present, a lower concentration might be more appropriate to avoid overshooting the target volume. Using a high concentration of acid or base can lead to difficulties in precise adjustments, but diluting a strong solution is a viable option. Overall, the choice of concentration should be tailored to the specific requirements of the media being prepared.
