Lecture 4 - Laboratory Liquids Flashcards
What is Reagent Water suitable for?
Use in a specified procedure that does not interfere with the specificity, accuracy, and precision of the procedure.
How is reagent water used directly?
To prepare reagents, buffers, and diluents.
How is reagent water used indirectly?
Washing and sanitizing analyzers/instruments and laboratory ware, generating autoclave steam, etc.
CLSI
Clinical and Laboratory Standards Institute
CLRW
Clinical Laboratory Reagent Water
SRW
Special Reagent Water
What are some characteristics of reagent water that should be tested at periodic intervals to evaluate the performance of the purification system?
- Microbial Monitoring/Pyrogens
- Resistivity
- pH
- Silica
- Organic Contaminants
Resistivity
Indicator of ionic contamination; more sensitive to H+ and OH- contamination than measuring pH.
Total Organic Carbon (TOC)
Indicator of organic contamination
Viable Plate Counts
Indicator of microbial contamination; epifluorescence and endotoxin testing optional (more sensitive and faster)
When measuring resistivity, what happens when purity increases?
The amount of dissolved ionized substances decreases and the ability to conduct electrical current also decreases.
What type of water satisfies most routine clinical laboratory testing?
Clinical Laboratory Reagent Water (CLRW)
Functions of Special Reagent Water (SRW)
Application requirements may require differing purities than CLRW
- Trace Organic Analysis
- DNA and RNA testing
- Trace Metals Analysis
- Low CO2 water
Uses of Instrument Feed Water
Analyzer/Instrument Uses
- Internal rinsing
- Dilutions
- Water bath functions
