Advanced Instruments OsmoPRO Multi-Sample - Standards and Quality Control; Standards & Controls; Sample Handling; Pipetting Technique

OsmoPRO® Multi-Sample Micro-Osmometer User’s Guide
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5. Standards and quality control
To run sample tests using the OsmoPRO, follow the steps and information listed in this chapter
carefully to achieve successful and accurate test results.
5.1 Standards & controls
To be accurate, all measurements ultimately must match highly reliable independent standards.
Advanced Instruments OsmoPRO Multi-Sample Micro-Osmometers are calibrated using
standards consisting of stable sodium chloride solutions of known freezing points which bracket
those of the expected unknowns. These standards are related to the most fundamental work on
freezing points of dilute solutions published, and are traceable to the National Institute of
Standards and Technology (formerly the National Bureau of Standards). We also use and
provide a sodium chloride reference solution for checking Osmometer accuracy at a point close
to the osmolality of normal blood serum.
Osmometers used for testing biological solutions should be checked additionally by making
determinations on actual biological solutions or controls formulated to simulate biological
solutions. Several biological controls are commercially available and may be recommended or
specified in your area. Contact your Advanced Instruments representative to obtain Protinol
Protein-Based Controls or Renol Urine Osmolality Controls. Check with your professional
associations and regulatory bodies for their guidelines, rules and regulations, and refer to the
recommendations contained herein.
5.2 Sample preparation
Sample preparation is not required. Body fluids such as serum or plasma may be measured
directly.
NOTE: Additives such as anticoagulants from collection tubes may contribute to the measured
osmolality. Particulate matter (normally eliminated by centrifugation in blood or
centrifugation/filtration in urine) may cause premature crystallization.
5.3 Sample handling / pipetting technique
The OsmoPRO comes with a 20 µL Pipette and we recommend using this pipette to guarantee
accuracy and precision.
• Ensure the specimen is properly mixed before pipetting into sample tubes.
• Transfer 20 µL of specimen onto the bottom of sample tubes. Avoid depositing liquid on
the sides of the tubes or dragging the pipette tip on any interior surface of the sample
tube when removing the pipette tip. Refer to Figure 5.1 below for proper pipetting
technique.