This medium is based on the work of Schiemann. It i
s used for the isolation and enumeration of
spp. from clinical samples and
from food. The selective components are sodium deso
xycholate, crystal violet, cefsulodin, irgasan and
novobiocin. Yersiniae ferment
mannitol with an intense, localised, acid productio
n in the centre of the colony which produces a red
‘bull’s eye’ appearance. The ratio of
transparent border to red centre varies with seroty
pe and environmental strains may appear rough with
an irregular edge. Most other enteric
bacteria, if they grow, produce a larger colony wit
h a diffuse pinkish centre and opaque outer zone.
Agar No. 2
Method for reconstitution
Weigh 58 grams of powder, disperse in 1 litre of de
ionised water. Allow to soak for 10 minutes, then b
ring to the boil for 1 minute only.
DO NOT AUTOCLAVE. Allow to cool to 47°C add 2 ampou
les C.I.N. supplement X120. Mix well, pour plates.
7.4 ± 0.2
Minimum Q.C. organisms:
(inhibition) WDCM 00013
Storage of Prepared Medium:
Plates – up to 7 days at 2-8°C in the dark.
Surface, streaking out for single colonies.
30°C aerobically for 24 hours.
Colony varies with
strain, may be rough
Gram +ve organisms
Schiemann, D.A. (1979). Synthesis of a selective ag
ar medium for
Can. J. Microbiol. 25: 1298-1304.
Schiemann, D.A. (1982). Development of a two step e
nrichment procedure for recovery of
from food. Appl.
Eniviron. Microbiol. 43: 14-27.
Mossel, D.A.A. (1987). Cefsulodin Irgasan Novobioci
n (C.I.N.) agar. Int. J. Food. Microbiol. 5: 208, 2