Virus-Like Particles in Blood of Two Acute Leukemia Patients

Abstract
A modified negative staining technique suited to demonstrating fragile virus particles in the electron microscope revealed particles having a surrounding membranous sac and an internal filamentous component of a consistent diameter of 75 Å in the blood of two patients with acute leukemia. No particles of this type were seen in the blood of four other patients with acute leukemia or in the blood of six normal individuals.