Abstract
Electron microscopy of hepatitis B antigen has revealed Dane particles with abnormal morphology. These aberrant Dane particles contain incomplete cores. They were seen in large numbers in the serum of an HBsAg-carrying renal dialysis patient and were less numerous but invariably present in other Dane particle-containing sera --12 from asymptomatic carriers, 2 chronic hepatitis patients and 1 patient with acute hepatitis. All 16 sera were shown to contain HBeAg.