Membrane Lauryl Sulphate Agar

//Membrane Lauryl Sulphate Agar

Membrane Lauryl Sulphate Agar

SKU: KM0072 Category:

Membrane Lauryl Sulphate Agar is used for the enumeration of Escherichia coli and other coliforms found in filter membranes used in water sample testing.
The broth base, originally named Membrane Enriched Teepol broth,(1) was updated when Teepol 610 was removed from the formulation and replaced by sodium lauryl sulphate.(2&3)
The peptones, yeast extract and lactose act as carbon, nitrogen and vitamin sources in this medium.
The phenol red is added as a pH indicator to detect the fermentation of lactose to differentiate the coliforms. Sodium lauryl sulphate is an inhibitory agent.

(1) Burman, N. P., 1967. Development of membrane filter techniques. II. Adaptation to routine and special requirements. Proc. Soc. Wat. Treat. Exam., 16:40
(2) Joint Committee of PHLS and the Standing Committee of Analysis. 1980. J. Hyg. Camb., 85:181
(3) Stanfield, G. and Irving, T. E., 1981. A suitable replacement for Teepol 610 in the selective isolation of coliforms from marine waters and sewage. Water Research. 15:469-474

Additional Information

Shelf Life (days)


Dehydrated Medium Appearance

Dehydrated Medium Colour

Dehydrated PH

Prepared Medium Appearance

Prepared Medium Colour

Prepared PH


Product Description

Organisms Ref. No Result
Escherichia coli ATCC 25922 Growth, yellow colonies
Citrobacter freundii ATCC 43864 Growth, yellow colonies
Enterococcus faecalis ATCC 29212 Inhibited


Recommended incubation

For E.coli spp.: Aerobically at 30 ± 1°C for 4 hours then at 44 ± 1°C for 14 – 18 hours.
For coliforms: Aerobically at 30 ± 1°C for 4 hours then at 37 ± 1°C for 14 – 18 hours.


Peptones 39.0
Yeast extract 6.0
Lactose 30.0
Phenol red 0.2
Sodium lauryl sulphate 1.0
Agar 15.0
Total 91.2
*Adjusted/supplemented as required to meet performance requirements



Suspend 91.2g of the medium in one litre of deionised / purified water.
Allow the medium to soak whilst mixing for 10 minutes.
Sterilise at 115°C for 10 minutes. Cool to 45-50°C and dispense into appropriate sterile containers.