What is the primary use of the Schales and Schales method?

• A. Chloride test
• B. Electrolyte panel
• C. Creatinine measurement
• D. Protein quantification

Answer: (A)

The Schales and Schales method is a classic colorimetric approach specifically used to determine chloride ion concentration in biological fluids. The procedure produces a color change that is proportional to how much chloride is present, so the measurement directly reflects chloride levels in the sample. This makes it a chloride test rather than a method for assessing other substances like creatinine or total protein, or as a general electrolyte panel. In practice, labs now often use automated techniques such as ion-selective electrodes for chloride, but the Schales and Schales method was developed precisely for measuring chloride content.