Printer-Friendly View

Method Summary

Method Source IDEXX Laboratories
Method NumberColisure
Revision InformationFeb. 28, 1994; current instructions with product
Method NameDescriptive Name: Coliform/E. coli Enzyme substrate test; CPRG-MUG test

Official Name: Colisure Test Kit Procedure

MediaMedia: WATER
SubcategoryMicrobiological
Citation Colisure Test Kit Procedure. 2001.
Method DownloadThis is a proprietary method.
Please visit the method owner's site for method documentation
Summary of MethodPresence/Absence: Add one packet of powder to the 100 ml water sample in a sterile, non-fluorescing vessel. Cap and shake the vessel to dissolve the powder. Incubate at 35C for 24 h. Read the results at 24 h (48 h maximum). If yellow color, the test is negative. If the sample has a red to magenta color, the presence of total coliforms is confirmed. If red to magneta, check for fluorescence by placing a 6W, 365 nm UV light within 5 inches of the sample. If blue fluorescence is observed, the presence of E. coli is confirmed. Quantification: See Standard Methods 20th ed. for MPN analysis (5,10,15 tube serial dilution) or pour the sample reagent mixture directly into a Quanti-Tray and seal according to instructions. Incubate and read the results as indicated above. Count the number of positive red-magenta wells and the number of red-magenta and blue-fluorescent wells. Determine the MPN/100ml using the table provided with the Quanti-Tray. For details, see the package insert. Requirements: Colisure kit from IDEXX. Sterile pipettes (for dilution only). Sterile, unbuffered water for dilutions. Incubator for 35oC controlled within 0.5oC. Long wavelength (365 nm) ultraviolet lamp for fluorescence readings. Cost of analysis: Presence/Absence approx. $4.00; Quantification approx. $5.00.
Scope and ApplicationAmbient, compliance monitoring (Standard Method 9223B): non-compliance: freshwater (surface & ground), drinking waters EPA Fed Reg (Aug 2001) only for E. coli in ambient waters: fresh surface waters; applicability must be demonstrated for other matrices. Approved for presence/absence of total coliforms and E. coli in drinking water as an alternate test procedure. Approved for presence/absence of total coliforms and E. coli in drinking water as an alternate test procedure. USEPA. 1999 (December 1). National primary and secondary drinking water regulations: analytical methods for chemical and microbiological contaminants and revisions to laboratory certification requirements; final rule. Fed. Reg. 64(230)67449-67467, USEPA (Aug. 30, 2001). Analytical methods for biological pollutants in ambient water; proposed rule. Fed. Reg. 66(169)45811-45829. Clean Water Act section 401. 40 CFR 136.1(c). (state certification, licenses) for compliance monitoring in programs 303(c), 304(a), and 501(a). 136.3 Identification of test procedures.
Applicable Concentration RangeFor samples in wells (excluding dilution factors): 1 to 2419 MPN/100 mL for 97-well Quanti-Tray; 1 to 200 MPN/100 mL for 51-well Quanti-Tray
InterferencesHeterotrophs at greater than 2 million/100ml
QC RequirementsControl cultures: Conducted on each lot of Colisure received as a minimum. Inoculate sterile water with either ATCC bacteria or Quanti-Cult (IDEXX)- E. coli (color & fluorescence), K. pneumoniae (color only) and P. aeruginosa (no color or fluorescence).
Sample HandlingSample preservation: chilled, 1oC to 4oC; 0.0008% (w/w) Na2S2O3 added to chlorinated waters EPA Fed Reg (Aug 2001). Techniques for collection: Standard Methods for the Examination of Water and Wastewater, 20th Edition. L. Clesceri, A. Greenberg, and A. Eaton (editors). APHA: Washington, DC. 1998. Sections 9020B8 and B9, 9060A and B.
Sample processing time: less than 5 minutes.
Max Holding TimeSample should be analyzed within 6 h after sampling and within 2 h from receipt of sample in lab for compliance or 24 h for routine monitoring (Standard Methods, 20th ed., Section 9060B); however, a 6 h holding time for all samples is highly recommended (Myers and Sylvester, 1997).
Relative Cost/EffortLess than $50
Sample Prep Method(s) 
 

Method Coliform/E. coli Enzyme substrate test; CPRG-MUG test has 2 analytes associated with it.

Analyte


Detection
Level


Bias Precision Pct False
Positive
E. coli
(68583-22-2)
1 MPN/100mLN/AN/A 
Total coliforms
(E761700)
1 MPN/100mLN/AN/A 
export_analytes
Precision Descriptor NotesEdberg, S. C.; Allen, M. J.; Smith, D. B. 1991. Defined substrate technology method for rapid and specific simultaneous enumeration of total coliforms and Escherichia coli from water: collaborative study. Jour. Assoc. Off. Anal. Chem. 74(3):526-9. McFeters, G. A.; Broadaway, S. C.; Pyle, B.H.; Pickett, M.; Egozy, Y. 1995. Comparative performance of Colisure TM and accepted methods in the detection of chlorine-injured total coliforms and E-coli Wat. Sci. Tech., 31 (5-6): 259-261.
Detection Level NoteFor samples in wells (excluding dilution factors), determined by: a) the largest volume that can be used without dilution to be in the concentration range for analysis; b) the lowest, statistically possible MPN/100 mL, when all replicates are negative. For example, if a 100 mL sample is used without dilution, the detection limit would be < 1 MPN/100 mL.
 
Close Window