Which accelerator is used in the Jendrassik Groff method?

• A. caffeine
• B. 50% methanol
• C. Ascorbic acid
• D. Sodium acetate

Answer: (A)

In the Jendrassik-Grof method for bilirubin, caffeine is added as an accelerator to speed up the diazo reaction that forms azobilirubin, producing a quicker and stronger color for measurement. This accelerates color development and improves assay reliability.

The other substances serve different roles: 50% methanol helps dissolve bilirubin and maintain reaction conditions but isn’t an accelerator; ascorbic acid could interfere with the color chemistry as a reducing agent; sodium acetate acts as a buffer.