PALCAM AGAR BASE
A base medium, with the addition of antimicrobial agents, is used to promote the selective cultivation and isolation of Listeria spp.Purpose
This is a selective and differential culture medium which contains appropriated nutrients for an adequate bacterial growth.
It is differential for the growing of Listeria spp., due to the product of esculin hydrolysis reacts with Fe3+ ions and a black coloured phenolic compound is produced. Selectivity is obtained by the addition of “PALCAM Agar Base, Selective Supplement”, because it contains antimicrobial agents which inhibit totally or partially the growth of the accompanying flora allowing the isolation of Listeria spp.
Formula (in grams per liter)
Instructions
Columbia Agar Base Suspend 33 g in 500 ml of distilled water. Let it stand for 5 minutes. Mix well. Heat with frequent agitation, and boil to dissolve completely. Dispense into containers and sterilize by autoclaving at 121°C for 15 minutes.
Cool to 50°C and aseptically add the content of 1 vial of PALCAM Selective Supplement, reconstituted according to instructions. Mix well and pour into sterile Petri dishes
D-Glucose D-Mannitol Esculin Iron ammonium citrate Phenol red Lithium chloride Final pH: 7.2 ± 0.2
Inoculation
Directly, streak on the surface of the agar.
Incubation
At 35-37 ºC, for 24-48 hours in atmosphere with 5-10% % CO2.
Results
Listeria monocytogenes ATCC 19114
Smooth, greenish colonies , with black haloes against red background
Listeria ivanovii ATCC 19119 Smooth, greenish colonies , with black haloes against red background
Escherichia coli ATCC 25922
Enterococcus faecalis ATCC 29212
Proteus mirabilis ATCC 43071
Appearance
Dehydrated medium: pink, free flowing, homogeneous powder.
Prepared medium: red coloured gel.
Storage:
Dehydrated medium: at 10-35 ºC.
Prepared medium: at 2-8 ºC.
Packaging
x 100g :Code: B02-236-05
x 500g :Code: B02-236-06