COUNTING OF NOSE SWIPES DOE/ERSP PROCEDURENO. 13 APPROVED: DATE DRAFTED: 30 January 1978 7 February 1978 by Don R. Martin (ERSP Manager) The Liquid Scintillation Counter (Beckman LS 100C) should be set up in window 3. discriminator should be set to 300. The upper level discriminator should be set to 1000. The lower level Procedure 1. The entire end of the nose swab (cotton swab, enclosing piece of wood) is put into a scintillation vial. Four ml of deionized water is added, capped and shook vigorously for 1 minute. Open and add 12 ml of scintillation cocktail. Cap. Shake vigorously for one minute. Label and enter sample number on counting sheet. Wipe sides of vial clean with tissue dampened with ethanol. Put vial into liquid scintillation counter, close cover to allow for adaptation to darkness, about 30 mintes, and count. Note: An 241Am standard and blank sample should be prepared in the same manner to determine the counting efficiency and background. A-13-1