PALCAM Agar Base

PALCAM Agar Base

SKU: KM0146 Category:

Palcam agar is a selective differential medium for the isolation of Listeria monocytogenes from food, clinical and environmental specimens.
The Columbia peptone mix and starch provide the required carbon, nitrogen and vitamins. Glucose is a fermentable carbohydrate. Differentiation of Listeria spp. from enterococci and staphylococci occurs through aesculin hydrolysis and mannitol fermentation. Listeria monocytogenes will hydrolyse aesculin and the associated reaction with the ferric ammonium citrate gives rise to a brown/black precipitate around the colonies. Listeria spp. do not however ferment mannitol. Mannitol fermentation is seen through a colour change of the colony or the area around the colony from red to yellow due to the production of acidic end products. Phenol red is the pH indicator in the medium.
Lithium chloride is included to inhibit enterococci. The associated Palcam selective supplement, LS0038, contains polymyxin B, acriflavine and ceftazidime to inhibit other Gram-positive and Gram-negative organisms that may be present in specimens.

Related Supplements :
LS0038 PALCAM Selective Supplement

Additional Information

Shelf Life (days)

Storage Temp (°C)

Dehydrated Medium Appearance

Prepared Medium Appearance

Dehydrated Medium Colour

Prepared Medium Colour

Dehydrated PH

Prepared PH

Product Description

Organisms Ref. No Result
Listeria monocytogenes NCTC 11994 Growth, grey colonies with dark halo
Listeria innocua NCTC 11288 Growth, grey colonies with brown halo
Escherichia coli NCTC 12241 Inhibited
Enterococcus faecalis NCTC 12697 Inhibited



Columbia peptone mix 23.0
Sodium chloride 5.0
Corn starch 1.0
Glucose 0.5
Mannitol 10.0
Aesculin 0.8
Lithium chloride 15.0
Ferric ammonium citrate 0.5
Phenol red 0.08
Agar 12.0
Total 68.0
*Adjusted/supplemented as required to meet performance requirements


Suspend 68g of the medium in one litre of deionised / purified water. Allow the medium to soak whilst mixing for 10 minutes. Heat with frequent agitation and boil for one minute to completely dissolve the medium. Sterilise at 121°C for 15 minutes. Cool to 45-50°C and aseptically add 2 vials of Palcam selective supplement (LS0038). Mix well and dispense into appropriate sterile containers.