1. MULTIGENT® Ammonia Ultra REF 6K8940
ARCHITECT® cSystem™
MULTIGENT® Ammonia Ultra
REF 6K8940

2. Agenda Clinical Utility Methodology Sample Handling Reagent Handling
Calibration
Quality Control
Reportable Range
Interference
Precision
Method Comparison
CAP Performance
Troubleshooting tips

3. MULTIGENT ® Ammonia Standard Supplied in the reagent kit
1 vial (1x 10 mL)
Controls
MULTIGENT Ammonia control REF 6K89-21
3 levels (1 x 5 mL)
Complaint handling:
Abbott has responsibility for initial complaint registration.
Sentinel (the vendor) will investigate level II complaints.

4. Assay disk MULTIGENT ® Ammonia MULTIGENT Assay Disk Version 2.00
8K50-02 Conventional/Alternate Units
8K51-02 SI/Alternate Units

5. Clinical Utility of Ammonia
Ammonia testing is used to:
Investigate change in behavior and/or consciousness especially in patients with impaired liver function and in children
Diagnosis the causes of a coma and is ordered in conjunction with other chemistry tests such as: glucose, electrolytes and kidney and liver function tests
Support the diagnosis of Reye’s syndrome* or Hepatic encephalopathy (swelling of the brain)
Reye’s Syndrome is a rare and serious childhood disease progressing through two states:
Stage I
Persistent or continuous vomiting and/or nausea, except for children under two who may have diarrhea or hyperventilate
Signs of brain dysfunction such as listlessness, lethargy or drowsiness
Stage II
Personality changes: irritability and aggressive behavior
Disorientation: confusion, irrational and combative behavior
Delirium, convulsions and coma
*Early diagnosis is vital, otherwise death or severe brain damage may follow.
Hepatic encephalophy is a syndrome observed in patients with fulminant or chronic liver disease characterized by disturbances in consciousness associated with rigidity, hyperreflexia most notably extension-flexion movements of the head and extremities (asterixis).
Source: 1.

6. Clinical Utility of Ammonia
Increased Ammonia in plasma may indicate:
Liver and/or kidney damage
Reye’s syndrome in children and adolescents (accompanied by decreased glucose levels)
Undiagnosed enzymatic urea cycle defect.
Infants – inherited deficiency/defect to urea cycle (extremely high level)
Decreased levels of ammonia may indicate:
Hypertension
Renal failure
Use of certain antibiotics

7. Clinical Utility of Ammonia
Ammonia levels are ordered for:
Children/Infants
If a newborn is irritable, vomiting, lethargic, or having seizures in the first few days after birth.
If physician suspects Reye’s syndrome.
Adults
If experiencing mental changes, disorientation, sleepiness or lapse into a coma.
If patient with liver disease displays neurological symptoms, ammonia will be ordered along with other liver function tests.
Source: Lab Test Online, en.wikipedia.org

8. MULTIGENT ® Ammonia Methodology
Methodology: Glutamate dehydrogenase
Chemical Reaction:
Methodology: Glutamate dehydrogenase
NH3 + a-ketoglutarate + NADH
H2O + glutamate + NAD+
GLDH = Glutamate dehydrogenase
NADH = Nicotanimide adenine dinucleotide
(GLDH)

9. MULTIGENT ® Ammonia Methodology
Description of Chemical Reaction:
Ammonia, in the presence of glutamate dehydrogenase (GLDH), combines with a-ketoglutarate and NADH to yield glutamate and NAD+. The decrease in absorbance (NADH NAD+) at 340 nm is proportional to the ammonia concentration in the examined plasma.
The reagent contains lactate dehydrogenase (LDH) in excess, to rapidly reduce endogenous pyruvate so that it does not interfere with the assay system.

10. MULTIGENT ® Ammonia Sample Handling
Specimen Requirements:
Plasma
With or without gel barrier
Lithium or Sodium Heparin or EDTA
Do NOT use Ammonium Heparin
Do not use hemolyzed samples (RBC contains ammonia levels 3 times that of plasma)
Completely fill collection tube with blood and immediately place in ice
Centrifuge cold and immediately separate the plasma
Sources of contamination include (but are not restricted to) cigarette smoking (patient and phlebotomy staff), air in the laboratory, and laboratory glassware.
Note: Glass tubes and K3-EDTA were not tested.

11. MULTIGENT ® Ammonia Sample Handling
Sample Tubes tested and found acceptable:
Vendor
Ref
Tube
BD Europe
367869
Na - heparin
368884
Li-heparin (17 IU/mL)
367374
Li -heparin with PST II gel barrier
368856
EDTA-K2

12. MULTIGENT ® Ammonia Sample Handling
Specimen storage:
Stored specimens must be inspected for particulates. If present, mix and centrifuge the specimen to remove particulates prior to testing.
Sample volume = 35 μg/dL
An Automated Dilution protocol is available. The system performs a 1:1.85 dilution of the specimen and automatically corrects the concentration by multiplying the result by the appropriate dilution factor.
Temperature
Maximum Storage
2 to 8°C
2 hours
-20°C
3 weeks

13. MULTIGENT ® Ammonia Reagent Handling
Reagent kits
Reagent is liquid, ready-to-use, single reagent kit.
Storage: 2 to 8°C.
Store reagent in the box.
Unopened kit is stable to the expiration date.
Remove any air bubbles with an applicator stick.
Reagent onboard stability is 15 days.
List Number
Kit Configuration
REF 6K89-40 R1
3 x 20 mL
CAL
1 x 10 mL
241 tests /kit

14. MULTIGENT ® Ammonia Calibration
Ammonia standard is liquid ready-to-use as a single calibrator
Ammonia standard is stable for 120 days at 2 to 8°C if contamination is avoided and vials are recapped immediately after use
Calibration curve is stable for 24 hours
Calibration is required with each change in reagent lot number
Calibrator value is verified using an internal standard obtained from ammonium sulfate puriss (ultrapure)
Calibrator must be clear – do not use if turbid

15. MULTIGENT ® Ammonia Calibration Curve - ARCHITECT ®

16. Quality Control
Ammonia Controls REF 6K89-21 supplied in 3 levels are available for use.
Controls are clear, colorless liquid – do not use if turbid.
Unopened controls are stable until expiration date when stored at 2 to 8°C.
Opened controls are stable 1 month at 2 to 8°C.
Do not mix components from different kit lot numbers.

17. Quality Control BioRad controls for ammonia are available
BioRad peer value information can be found on WWCS Webpage
BIO-RAD
Control Product Name
Catalog Number
Configuration
Liquichek Ethanol/Ammonia Control
Tri-level: 545x
L-1: 544
L-2: 545
L-3: 546
3 x 3 mL
6 x 3 mL

18. MULTIGENT ® Ammonia Reportable Range
Reportable Range = 8 to 1,700 μg/dL*
(4.7 to µmol/L)
Limit of Detection = 7.5 μg/dL*
(4.40 µmol/L)
LOD calculated on 20 replicates of normal saline reported as “mean zero value + 3 SD”
*Note: SI units are μmol/L
To convert results from μg/dL to µmol/L, multiply by

19. MULTIGENT ® Ammonia Interference
Interfering substances:
MULTIGENT Ammonia Ultra is not affected by the presence of the following interferents up to the concentrations indicated below:
Interfering Substances
Interferent
Concentration
Ascorbic acid
40 mg/dL
2271 μmol/L
Bilirubin
20 mg/dL
342 μmol/L
Pyruvate
6.58 mg/dL
750 μmol/L
Human triglyceride
700 mg/dL
7 g/L
Hemoglobin: hemolyzed samples should not be used as erythrocytes contain ammonia levels appproximately 3 times that of plasma.

20. MULTIGENT ® Ammonia Precision
Representative data from a 5 day study with two runs and four
replicates of each control per day are summarized below.
Control
Level 1
Level 2
Level 3 N
Mean (μg/dL) 40
56.10
268.63
368.95
Within Run SD
%CV
1.15
2.05
2.06
0.77
1.99
0.54
Between Run SD
2.53
4.50
2.88
1.07
1.43
0.39
Total SD
2.67
4.76
3.40
1.27
2.36
0.64

21. MULTIGENT ® Ammonia Method Comparison
Plasma results from the Ammonia Ultra assay on an ARCHITECT c System were
compared with the results from a commercially available glutamate
dehydrogenase (GLDH) methodology and a commercially available micro-
diffusion methodology.
ARCHITECT vs.
GLDH Assay
Micro-diffusion assay N 65 60
Y – intercept
2.5257
Correlation Coefficient
0.9986
0.9831
Slope
0.9927
0.8956
Range (μg/dL)
38 to 1655
19 to 680

22. MULTIGENT ® Ammonia CAP Performance
CAP Proficiency Testing (PT) for MULTIGENT Ammonia assay was
performed in-house on the Architect c8000 analyzer using
CAP PT materials: CHM-01, CHM-02, CHM-06 and CHM-07.
2008 CZ-A 2008 Survey results (Information Only)
MULTIGENT All Method Mean
CHM CHM
2008 CZ-B 2008 Survey results (Information Only)
MULTIGENT All Method Mean
CHM
CHM
NOTE: Result units μmol/L

23. Troubleshooting Tips Poor venipuncture technique
Completely fill the collection tube with blood
Do not use heparin lock
Do not draw blood into a syringe and transfer to
an anticoagulant tube
Metabolism of nitrogenous constituents will result in higher ammonia levels
Specimen must be put on ice immediately and centrifuged without delay
If storing sample immediately separate red cells from sample or analysis of sample should be performed as soon as possible
Smoking
Patient should restrict smoking prior to fasting venipuncture
Smoking 1 cigarette 1 hour prior to venipuncture can increase blood ammonia levels from 10 to 20 mg/dL
End of Document