Enzyme Substrate Detection System:

Comprising a programmable quantitative sealing machine,51-or 97-well detection plates,100 mL volumetric flasks,and enzyme substrate detection reagents.Applicable water samples include:drinking water,source water,bottled water,reclaimed water,secondary water supply,pipeline water,wastewater,food processing water,livestock water,medical water,etc.

This detection method utilizes Escherichia coli's production ofβ-galactosidase to degrade chromogenic substrates,causing the culture medium to turn yellow.It utilizes the principle that Escherichia coli producesβ-glucuronidase to degrade the substrate,causing the culture medium to fluoresce under 366 nm UV light.This enables the qualitative and quantitative detection of total coliform bacteria,fecal coliform bacteria(thermotolerant coliforms),and Escherichia coli in water.

Accessory Components:

Equipment corresponding to the enzyme substrate detection principle is procured.Applications:

Programmable Sealing Machine:Used for sealing quantitative detection plates.

Enzyme Substrate Detection Reagent:Used for selectively detecting target bacteria in water.

51 or 97 Quantitative Detection Plate:Used to determine the quantity of target microorganisms.

100 mL Quantitative Bottle/Sampling Bottle:Provides a specialized dissolution environment for water samples and reagents.

UV handheld analyzer with darkroom:Used to observe fluorescence in a darkroom when detecting Escherichia coli.

Operating Procedure:

Step 1:Add water sample to a 100 mL sampling bottle.Add enzyme substrate detection reagent,screw on the cap,and shake until completely dissolved.

Step 2:Transfer the sample to the quantitative detection plate.

Step 3:Use a programmable quantitative sealing machine to dispense samples and seal the quantitative detection plate.

Step 4:Incubate the sealed quantitative detection plate at 36±1°C.For fecal coliform(thermotolerant coliform)testing,set the incubator to 44.5°C and incubate for 24 hours.

Step 5:Count the number of positive(yellow or fluorescent)wells against the color chart.Consult the 51-well or 97-well MPN table(depending on the plate type)to determine the coliform count per 100 mL.Record the data from the MPN table.

Step 6:Calculate the final result based on the dilution factor using the formula:

Coliform bacteria(cfu/L)=MPN value×dilution factor×1000 mL/100 mL