| Autor: |
S D, Winter, C, Kerr, M, McAvoy, M D, Gallomore, C, Smith, R B, Lepoff |
| Rok vydání: |
1985 |
| Předmět: |
|
| Zdroj: |
Clinical chemistry. 31(11) |
| ISSN: |
0009-9147 |
| Popis: |
We systematically studied the "carryback" effect of ethylene glycol-based controls on the preceding sample on an SMA II continuous-flow analyzer. Including Beckman Level 1 unassayed liquid control material as a sample lowered the 12 analyte values of the preceding sample by an average of 2.7%, Level 2 (the most viscous) by an average of 4.4%, and Level 3 by 3.2%. Water-reconstituted lyophilized control material caused no carryback effect, but lyophilized control reconstituted with 330 mL/L ethylene glycol decreased the preceding sample's results by 4.1% (average carryback). We believe that carryback is caused by the drag placed on the sample line by a viscous sample, which decreases the volume of the preceding sample that is delivered to the reagent or pre-dilution mixing coils. Our findings were confirmed on another SMA II. Limited study of a SMAC analyzer gave inconclusive results, but further evaluation of continuous-flow systems for carryback is warranted. Carryback substantially increases total analytical variability. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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