Rapid Silver Stain for the DNA of Microorganisms Cultured from AIDS or OtherImmunocompromised Patients

摘要

Although a number of cytochemical methods have been introduced for nuclei at theultrastructural level, many of these are topographic, i.e. identify nuclei rather than nuclear chromatin and DNA. An improved silver method for the Feulgen reaction for the light and electron microscopy of DNA was introduced in 1984 (FETS reaction). It required application of the silver methenamine for 15 min. under UV-irradiation and subsequent development of the stain overnight in glycerine. This type of methodology has been considerably accelerated by the application of silver solutions especially silver methenamine solutions prepared from the solid under microwave(MW) irradiation. The current procedure employs 1 min. formalin fixation of a smear of the sample on a slide or coverslip. The fixed smear is then rinsed 1 hr. in buffer. Aldehyde or pseudoaldehyde groups of apurinic acids are generated by the action of 2.5N HCI for 10 min. on the DNA.