ASTM D6503-19 pdf free download.Standard Test Method for Enterococci in Water Using Enterolert.
ASTM D6503-19 covers a simple procedure for the detection of enterococci in water and wastewater. It is based on IDEXX’s patented Defined Substrate Technology (DST).2 This product, Enterolert, utilizes a nutrient indicator that fluoresces when metabolized. It can detect these bacteria at one most probable number (MPN)/100 mL within 24 h. The presence of this microorganism in water is an indication of fecal contamination and the possible presence of enteric pathogens.
4. Summary of Test Method
4.1 This test method is used for the detection of enterococci such as E faecium, E faecalis in drinking water, source water. recreational waters (marine water and fresh)， wastewaters, and bottled water. When the reagent is added to the sample and incubated at 41 + 0.5″ for 24 h and up to 28 h, Enterolert can detect these bacteria at 1 MPN/100 mL. Fluorescence is produced when enterococci metabolizes the nutrient indicator. Enterolert can be used as a presence-absence test or fo quantification(5-tube, 10-tube MPN, I5-tube serial dilution or the Quanti-Tray system).
8. Reagents and Materials
8.1 Purity of Water-Unless otherwise indicated, references to water shall be understood to mean reagent water conforming to Specification DI 193, Type IV. Sterilize the water by either autoclaving or by sterile filtration(0.22 micron-filtered water).
8.2 Enterolert Test Kit
9. Precautions
9. 1 The analyst must observe the normal good laboratory practices and safety procedures required in a microbiology laboratory while preparing, using, and disposing of cultures reagents and materials and while operating sterilization equip ment and other equipment.
13. Calculation
13.1 For P/A, there are no calculations. For quantification. refer to Quanti-Tray MPN tables and for the 5, 10, and 15 tube test results refer to the respective MPN tables.
14. Report
4. 1 Report as posI itive or negative for presence/absence testing.
14.2 Reporting of results is based on calculation of enterococci density determined from the appropriate MPN tables.