In the Jendrassik-Grof bilirubin method, moderate hemolysis causes which effect?

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Multiple Choice

In the Jendrassik-Grof bilirubin method, moderate hemolysis causes which effect?

In the Jendrassik-Grof bilirubin method, bilirubin reacts with diazotized sulfanilic acid to form a colored azobilirubin product whose absorbance is measured. Hemoglobin released from lysed red cells can interfere with this chemical reaction itself. Hemoglobin can act as a reducing agent or otherwise interact with the diazonium reagent, reducing the extent of diazo coupling and thus inhibiting formation of azobilirubin. Because less colored product forms, the measured absorbance drops and the bilirubin concentration is falsely low. Other possibilities like simple optical interference or blanking to correct interference don’t address this chemical inhibition. Also, bilirubin is not stored in red blood cells, so release of bilirubin from RBCs isn’t a valid mechanism here.

In the Jendrassik-Grof bilirubin method, bilirubin reacts with diazotized sulfanilic acid to form a colored azobilirubin product whose absorbance is measured. Hemoglobin released from lysed red cells can interfere with this chemical reaction itself. Hemoglobin can act as a reducing agent or otherwise interact with the diazonium reagent, reducing the extent of diazo coupling and thus inhibiting formation of azobilirubin. Because less colored product forms, the measured absorbance drops and the bilirubin concentration is falsely low.

Other possibilities like simple optical interference or blanking to correct interference don’t address this chemical inhibition. Also, bilirubin is not stored in red blood cells, so release of bilirubin from RBCs isn’t a valid mechanism here.

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