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• Use the proper diluent material for your sample type.
–
For plasma and serum samples, use normal saline.
–
IDEXX does not recommend manually diluting whole blood in a Catalyst* whole blood
separator—only dilute the separated plasma.
–
For urine, use Catalyst* Urine P:C Diluent.
• Use an accurate measuring device, such as a calibrated pipette or syringe.
• For best results, start with a 1:2 dilution (1 part sample to 1 part diluent)—do not exceed 10
parts diluent.
• Do not dilute samples that are undergoing ammonia, phenobarbital, fructosamine, total T
4
, or
electrolyte testing.
• Do not dilute small samples to achieve a minimum sample volume. Such dilutions on normal
analyte concentration cannot be read accurately. When dilution is needed to determine some
analytes at very high concentration, the sample should be diluted manually.
• An automated dilution run will be canceled if:
–
There is insufficient diluent/sample volume.
–
There are too many slides in the run.
Minimum Sample Volume for Dilutions
The minimum sample volume varies based on the dilution factor and the number of slides that are
being diluted (see table below).
Parts
Parts Diluent =
Diluent Ratio
Maximum
Number of
Slides per
Dilution
Minimum Sample Volume
Diluent
Volume
Serum, Plasma,
or Urine
Whole Blood
1 + 1 = 1:2
5
155 µL
700 µL
300 µL
1 + 3 = 1:4
10
130 µL
700 µL
300 µL
1 + 5 = 1:6
10
130 µL
700 µL
300 µL
1 + 9 = 1:10
10
100 µL
700 µL
300 µL
Preparing Manual Dilutions
To Prepare a 1:2 Dilution
1. Accurately measure the desired amount of sample to be diluted and gently transfer it to a
sample cup.
2. Accurately measure an equal amount of diluent and transfer it to the sample collected in step 1.
3. Thoroughly mix the sample and diluent.
4. Analyze the sample.
Using the Catalyst One* Analyzer
