Academic Materials
Accurate and stable creatinine reagent
Serum creatinine is crucial in glomerular filtration rate (GFR) estimation. There are two methods for determination, Jaffe and Enzymatic.
However, the Jaffe method is unstable and has much influence. So, why not use an accurate and stable Enzymatic reagent to evaluate GFR?
They measured value-assigned creatinine specimens in the range 52-262 μmol/L using Jaffe and Enzymatic methods.
The Jaffe method tends to overestimate creatinine at low concentrations:
21%, 12%, 10% for the creatinine target value 52, 73 and 94μmol/L near normal values of creatinine.
However, the Enzymatic method has only small bias and provides stable results.
Effect of Interference
The results measured through the Jaffe and Enzymatic methods for each reagent confirm the extent to which creatinine is interfered with proteins and glucose.
The Jaffe method has a significantly larger bias for both additive as the concentration increases. In contrast, the Enzymatic method shows stable results due to its high specificity.
Method
The in-house clinical chemistry analyzer CA-270 and the dedicated creatinine reagents are used along with albumin and glucose with high laboratory grade.
Onboard stability of the Jaffe and Enzymatic methods
(1) Jaffe method
The Jaffe method is typically unstable as the Jaffe reagent contains alkaline ingredients and continuously absorbs bicarbonate from air to be neutral.
(2) Enzymatic method
In contrast, the Enzymatic method takes buffered solution and enables more stable measurement.
Reagent Package Information
| Product Name | Product No. | FURUNO Analyzer | Configuration | |
|---|---|---|---|---|
| R1 | R2 | |||
|
|
CF16917080-F3 | CA-270 CA-400 CA-800 |
3 × 60 mL | 3 × 20 mL |
| CF16917028-F3 | 3 × 20 mL | 3 × 8 mL | ||
|
|
CF05917084-F | CA-270 CA-400 CA-800 |
6 × 67 mL | 6 × 17 mL |
| CF05917084-F3 | 3 × 67 mL | 3 × 17 mL | ||
| CF05917084-F4 | 4 × 20 mL | 4 × 7 mL | ||
| CF05917084-F8 | 8 × 20 mL | 8 × 7 mL | ||
Reagents are manufactured by Centronic GmbH certified according to ISO13485.
FURUNO Analyzers
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Clinical Chemistry Analyzer Model CA-800
800 tests/hour throughput capability (maximum 1200 tests/hour with ISE). Fully direct automatic HbA1c measurement without manual sample pretreatment.
Optional rack system available for place and go sample process. -
Clinical Chemistry Analyzer Model CA-400
Mid-range throughput (400 tests/hour, 560 tests/hour with ISE).
Main instrument for midsize workload laboratory or backup unit for high workload laboratory. -
Clinical Chemistry Analyzer Model CA-270
Compact desk-top instrument with 270 tests/hour (maximum 450 tests/hour with ISE).
Functionality of a high throughput instrument in compact desktop form ideal in any type of laboratories.