Nit cement diagram (IMAGE) University of Reading Caption Nit of human louse showing the cement covering the egg shell and hair shaft, including a human cell (nucleus, arrow). Fluorescence microphotograph in the UV light, specimen prepared with a fluorescence dye that binds to DNA (DAPI). Nuclei of cells and bacteria, Riesia -primary symbiotic bacterium of lice, show signal (arrows). Credit University of Reading Usage Restrictions Use with credit License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.