<prompt> A chest physician performs bronchoscopy in the procedure room of the out patient depament. To make the instrument safe for use in the next patient waiting outside, the most appropriate method to disinfect the endoscope is by -70 alcohol for 5 min2 glutaraldehyde for 20 min2 formaldehyde for 10 min1 sodium hypochlorite for 15 min  <response>: Glutaraldehyde is especially effective against the tubercle bacilli, fungi, and viruses. It is less toxic and irritant to eyes and skin than formaldehyde. It has no deleterious effects on the cement or lenses of instruments such as cystoscope and bronchoscopy It can be safely used to treat corrugated rubber,nanestheticubes, face masks, plastic endotracheal tubes, metal instruments a, d polythene tubings REF:Ananthanarayan and Panickers Textbook ofMicrobiology 8th Edition pg no:36 