Automation of urinalysis, including urine microscopy, is becoming more common, even in smaller laboratories. These systems currently use reagent strips, as are used for manual or semi-automated methods, for chemical analysis.
The urine constituent evaluation on an automated system offers several advantages over manual microscopic sediment examination.
- A greater number of elements are viewed and evaluated by the instrument than can be viewed and evaluated with a manual sediment examination, providing a more accurate enumeration.
- Single-particle analysis detects small numbers of constituents that may be missed with a manual microscopic examination.
- Standardization of the analysis removes the variables associated with manual methods. Even though attempts are made to standardize manual methods, they are still manual and subject to examiner variations.
Automation can improve the accuracy of the count, but test results are still dependent on the quality of the sample that is used. Pre-examination (formerly preanalytical) errors, including incorrect identification of the specimen, prolonged room temperature storage of the sample prior to testing, and insufficient mixing of the sample before analysis, impact the accuracy and reliability of test results. Each manufacturer will specify which urine chemical reagent strips are acceptable for use on their instrumentation. The use of an unapproved reagent strip could also cause erroneous results.
