S ¼ concentration (nematode/ml) in initial suspension.
(X + 1) ¼ dilution.
9. Make dilutions with the given number of nematodes per
ml from the counted number, by using the given formula:
A ¼
D Â C
B
A ¼ ml of suspension of known concentration, the suspension to be diluted.
D ¼ preferred concentration in new dilution.
C ¼ final volume (ml) of new dilution.
B ¼ number of nematodes per ml in suspension.
Therefore, to make a new dilution, use:
C – A ¼ ml of water to be added.
3.7 Storage of Soil
Nematodes
Many nematodes remain in good condition for several days when
stored in shallow, fresh tap water at about 5–10
C. Contaminating
bacteria can be suppressed by adding three drops of 5% streptomycin sulfate solution per 5 ml of nematode suspension. For longterm storage (germplasm collection, maintenance of genetic lines,
reference material or inoculum), nematodes can be stored in liquid
nitrogen. Cryopreservation has been shown to work for several
nematodes.
Fig. 10 Nematode counting devices
Isolation and Storage of Soil Nematodes
67
(X + 1) ¼ dilution.
9. Make dilutions with the given number of nematodes per
ml from the counted number, by using the given formula:
A ¼
D Â C
B
A ¼ ml of suspension of known concentration, the suspension to be diluted.
D ¼ preferred concentration in new dilution.
C ¼ final volume (ml) of new dilution.
B ¼ number of nematodes per ml in suspension.
Therefore, to make a new dilution, use:
C – A ¼ ml of water to be added.
3.7 Storage of Soil
Nematodes
Many nematodes remain in good condition for several days when
stored in shallow, fresh tap water at about 5–10
C. Contaminating
bacteria can be suppressed by adding three drops of 5% streptomycin sulfate solution per 5 ml of nematode suspension. For longterm storage (germplasm collection, maintenance of genetic lines,
reference material or inoculum), nematodes can be stored in liquid
nitrogen. Cryopreservation has been shown to work for several
nematodes.
Fig. 10 Nematode counting devices
Isolation and Storage of Soil Nematodes
67