Hydroquinone 0.15 %, consisting of Aqua bidest / ultrapure water and hydroquinone (1,4-dihydroxybenzene), is an important component of the developer solution for WARTHIN-STARRY silver staining. WARTHIN-STARRY silver staining is a histological staining technique used in microscopy for the detection of certain bacteria, such as Helicobacter pylori, spirochaetes and Bacillus piliformis.

In WARTHIN-STARRY silver staining, hydroquinone 0.15% plays a crucial role as it serves as a reducing agent to reduce silver nitrate into metallic silver. This process is necessary to produce visible staining of the bacteria in the microscopic image. The selective reduction allows differentiation of the bacteria from other structures in the tissue.

Chemically, during WARTHIN-STARRY silver staining, a redox reaction occurs in which hydroquinone donates electrons to silver nitrate and is itself oxidized to quinone. This results in the formation of metallic silver, which is selectively deposited on the target bacteria, making them visible under the microscope.

Hydroquinone 0.15% offers advantages over other reducing agents due to its controlled and selective reduction properties. This enables precise staining of bacteria and improves the quality of microscopic images in WARTHIN-STARRY silver staining.