Cuvettes must be cleaned in an ultrasonic cleaning bath.

• A. True
• B. False
• C. Not necessary
• D. Sometimes

Answer: (B)

Keeping cuvettes clean is essential to prevent any residue from affecting absorbance readings. An ultrasonic cleaning bath is a powerful option because the cavitation can remove stubborn residues that brushing and rinsing might miss. However, it’s not required for every cuvette or cleaning situation. Some cuvettes are delicate or made of materials that can be damaged by ultrasonic energy, and many labs successfully clean cuvettes by rinsing with deionized water, washing with a mild detergent, rinsing again, and drying with a lint-free tissue. If residues are tough, ultrasonic cleaning can be used, but only when allowed by the cuvette material and the lab’s standard operating procedures, with proper solvent choices and durations to avoid damage. Because of that variety in materials and practices, stating that cuvettes must be cleaned in an ultrasonic bath is not correct.