MacConkey Agar Contact Plate 55mm [Pack of 20]

Description

MacConkey Contact Agar – RT is designed for the isolation of Enterobacteriaceae on dry surfaces
and personnel in controlled environments and for Room Temperature storage.

Ten contact plates each with a diameter of 55 mm are single-bagged in transparent, hydrogen peroxide impermeable sleeves (non-irradiated). The sleeves consist of polypropylene with a barrier of PE-EVOH-PE.
The formulation of the basic medium (MacConkey Agar) is prepared according to the recommendations of the current European and United States Pharmacopoeia (EP, 2.6.13. and USP, 62).

Mode of Action
MacConkey Agar is a weakly selective medium for the isolation of Enterobacteriaceae or specifically E. coli in pharmaceutical products, food, water, and other materials.
Enterobacteriaceae can be clearly identified even in the presence of Salmonella and Shigella.
The MacConkey Agar inhibits the growth of gram-positive bacteria by the addition of crystal violet and bile salts, whereas the growth of most gram- negative bacteria is supported. Bacteria degrading lactose to acids grow in pink to red colored colonies. Additionally E. coli and other acid forming bacteria will show a zone of precipitated bile salt around the colonies. Bacteria not degrading lactose will grow colorless. The family of Enterobacteriaceae is defined by the growth on MacConkey Agar.
It is not possible to detect low numbers of Salmonella while the accompanying microbial flora is abundant.

Typical Composition
Pancreatic Digest of Gelatin 17 g/l
Peptones (Meat and Casein) 3 g/l
NaCl 5 g/l
Lactose monohydrate 10 g/l
Bile Salts 1.5 g/l
Crystal Violet 1 mg/l
Neutral Red 30 mg/l
Agar 13.5 g/l
The appearance of the medium is clear and reddish brown. The pH value is in the range of 6.9- 7.3. The medium can be adjusted and/or supplemented according to the performance criteria required.

Application and Interpretation
Each plate is provided with a label including a data matrix code for paperless plate identification.
The code consists of a two-dimensional 20-digit serial number, which harbors the following information:
Digits 1-3: here code 866 (corresponds to article 146427); digits 4-9: lot number; digits 10- 14: batch specific individual number; digits 15-20: expiration date (YY/MM/DD).

Please check each agar plate before using it on sterility and pay attention to aseptic handling in
order to avoid false positive results.
According to ISO 14698 the plates are opened and the agar surface is pressed on the dry surface to be tested for some seconds with a steady pressure. Afterwards the plates are closed and transferred to an incubator. Residues of culture medium should be removed from the surface after sampling.
According to the recommendations of the current EP and USP MacConkey Agar is incubated for 18-72h at 30-35 °C. Growth of colonies indicates the possible presence of E. coli. This is confirmed by suitable identification tests.

Storage and Shelf Life
The product can be used for sampling until the expiry date if stored upright, protected from light and properly sealed at +15 °C to +25 °C.
Condensation can be prevented by avoiding quick temperature shifts and mechanical stress.
The testing procedures as described on the CoA can be started up to the expiry date printed on the label.

Disposal
Please mind the respective regulations for the disposal of used culture medium (e.g. autoclave for 20 min at 121 °C, disinfect, incinerate etc.).