SUPPLY OF PROFICIENCY TESTING SCHEME SAMPLES PHE – FOOD AND WATER MICROBIOLOGY EXTERNAL QUALITY ASSESSMENT SCHEME: DRINKING WATER, BOTTLED WATER AND RECREATIONAL WATER. MEDIA: YEAST EXTRACT AGAR, NUTRIENT BROTH NO2, TRYPTONE WATER, SHEEP BLOOD AGAR, MAC CONKEY AGAR, ALKALINE PEPTONE WATER, RE-INFORCED CLOSTRIDIAL AGAR, PERFRINGES AGAR BASE (TSC & SFP) AND PERFRINGES TSC SELECTIVE SUPPLEMENT AT ANALYTICAL SERVICES MICROBIOLOGY LABORATORY.