Question | Answer |
Comprehensive set of policies, procedures, and practices necessary to make sure a labs results are reliable | Quality assurance |
Set of lab procedures designed to ensure that a test method is working properly and results meet the diagnostic needs of the physician | Quality control |
Pre-analytical | Specimen collection and identification, specimen transport, specimen storage |
Analytical | Test procedures, Reagents, Instrumentation |
Post-Anyalytical | Technical competence of lab personnel, continuing education of lab personnel |
How do you perform QC on a refractometer | Check with distilled water; should read 1.000 |
How do you perform QC on a reagent strip | Purchase control urine, prepare positive and negative controls and test once every 24 hours |
How do you perform QC on a microscopic sediment exam | Purchase urine with a known sediment in it |
Why is CCMS the specimen of choice for urinalysis | reduces the incidences of cellular and microbial contamination |
What can osmometry tell you that specific gravity test cant | Osmometry is a more exact measurement. It gives you a value instead of a range |
Heat generate from crystallization that brings the sample to it's freezing point | heat of fusion |
Normal range for urine | 500-850 mOsm/kg of water |
First morning specimens | >850 mOsm/kg of water |
Random specimen | 300-900 mOsm/kg of water |
Normal range for serum | 280-300 mOsm/kg of water |
Urine to serum osmolality ratio | 1.0-3.0 |
Explain how a freezing point osmometer works | Serum is put in a cooling container, cooled below freezing point, stirred and partially crystalizes. Heat is generated (heat of fusion) and brings the sample to it's freezing point. Osmolality can be calculated from freezing point depression |