What effect does moderate hemolysis have on bilirubin measurement using the Jendrassik-Grof method?

In the context of bilirubin measurement using the Jendrassik-Grof method, moderate hemolysis can indeed lead to a falsely low bilirubin result. This occurs because the hemoglobin released from lysed red blood cells can inhibit the diazo reaction, which is a crucial part of the Jendrassik-Grof method. The presence of hemoglobin in the sample competes with the bilirubin for the diazo reagent, which results in a reduced color change that signifies the amount of bilirubin present. This interaction can mask the actual concentration of bilirubin, leading to an underestimation when the measurement is performed.

It's important to understand that although moderate hemolysis may seem like it should increase bilirubin levels due to the release of bilirubin from the red blood cells, the inhibitory effect of hemoglobin on the diazo reaction is more significant in this method, steering the result toward being falsely low instead. This interaction highlights the sensitivity of the Jendrassik-Grof method to interferences, particularly from substances like hemoglobin that can interfere with colorimetry results.