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The U.S. Food and Drug Administration updated the medical device shortage list to now include testing supplies including serological pipettes, which has greatly impacted both the healthcare and life sciences industry. The COVID-19 pandemic has, obviously, had a major impact on the global supply chain. With increased demand for testing, the materials available worldwide dwindled. Coupled with this year’s winter storms in Texas, which is host to two of the three biggest polyethylene plants, the manufacturing of clear plastic polymer pipette tips, serological pipets, and other products slowed down dramatically. The increased demand and decreased supply are making it difficult for labs to keep pace. Researchers are facing higher prices on their laboratory supplies, with exceptionally increased wait times. This means that scientists are burning through funds faster, with delayed results. Despite the setbacks, the demand for the accuracy and precision of laboratory supplies continues increasing. Keep reading to explore the key factors in optimizing serological pipet performance.
Pipettes vs Pipet
Serological pipets are a single glass or plastic tube that serve as basic instruments for many lab applications. Serologic pipets are the tool of choice for the following tasks.
- Moving liquid between different receptacles and containers
- Mixing chemical solutions
- Stacking reagents with different density composition
Pipette tips and serological pipets can only be used once to prevent cross-contamination. This means that labs can use up many cases in one day. Thus, labs need a consistent supply to keep research experiments running smoothly.
What Impacts the Accuracy and Precision of Serological Pipets?
Several factors play a role in the precision and accuracy of serological pipets. Without accuracy, the results are meaningless. Pipettes must give a reading that’s close to a nominal or true volume measured by the volume setting. Precision describes the ability to repeat the test and get the same results. The repetitive test results must fall within a set standard deviation. It’s important to record environmental and liquid variations when testing. The following factors can impact the accuracy and precision of your results.
A liquid’s volume density (mass/volume ratio) impacts the aspiration into the tip. To test this, aspirate a small volume of a higher-than-water density and an equal amount of water. The earth’s gravity, flexibility, and amount of dead air volume affect the results.
Temperature also plays a key role in altering the density of liquids. This changes the accuracy of pipetting. The temperature difference between the liquid and the delivery device greatly impacts outcomes. The dead air volume (air gap) expands between the piston and the liquid surface. This causes the amount of liquid aspirated into the tip to increase or decrease. Thus, your result’s accuracy and precision become compromised.
Air pressure changes at different geographic altitudes. High altitudes lower the air pressure causing the conversion factor Z to decrease. The boiling point of some liquids can become close to room temperature at specific altitudes. This will cause a dramatic increase in evaporation loss.
MarathonLS Serological Pipets
MarathonLS offers a size range from 1 mL serological pipets to 100 mL. Each pipet has clear ascending and descending graduations marked on the side. This ensures accurate measurement when dispensing or aspirating. All MarathonLS pipets meet certification standards that guarantee that they’re RNase-free, DNAse-free, non-cytotoxic, and non-pyrogenic. They’re also latex-free and adhere to BSE/TSE standards. Every serological pipet is produced in a class 100,000 cleanroom environment. The facilities meet ISO13485 and ISO9001 requirements for quality management systems. Pipette tips are available in high-grade filtered, unfiltered, extended length, and low retention. You can also get universal-fit tips for most major pipettors. Their hydrophobic surface promotes accurate pipetting. Every item has a printed batch number to make it traceable. The graduation calibration also allows for dispensing within ±2 percent.
Choosing the Right Size Pipette
To ensure accuracy and precision, it’s key to choose the right tool for measuring each volume. Always select the smallest pipet appropriate for the job to reduce errors. When measuring 4.5 mL of liquid, a 5 ml serological pipette is more accurate than a 10 mL. If you’re working with very small volumes, you’ll want to choose a small pipet. Thus, a serological pipette of 2ml or similar size is often best. Its small diameter and precise graduations reduce errors when judging the sample’s meniscus.
Most Common Serological Pipette Sizes
The most common volumetric pipettes include the following:
- 10 mL serological pipette
- 25 ml serological pipette
- 50 ml serological pipette
Scientists often use these to produce laboratory solutions from a base stock. They’re also valuable in preparing a solution for titration.