Why Water Quality Determines the Accuracy of Laboratory Results 

By L Satish, Head – Lab Water Solutions, Merck Life Science India 

Both pharmaceutical and clinical diagnostic laboratories rely on purified water as their primary reagent. Therefore, it is surprising that the purity of the water used in laboratories is often overlooked as a factor that could impact the accuracy of analytical measurements.

Globally, there are over 2.1 billion laboratory experiments conducted each year requiring purified water for applications like chromatography, molecular biology, and pharmaceutical analysis. Furthermore, the global laboratory water purification systems market is estimated to be worth USD 37.7 billion in 2025, with a projection to grow to USD 72.82 billion by 2034. As the global laboratory market has been growing at an accelerated pace, there has also been a growing demand for ultrapure laboratory water.

As analytical techniques have become more sensitive, such as HPLC, mass spectrometry, PCR, and cell culture, the detection limits for trace impurities are becoming lower. As laboratories continue to push the boundaries for precision in their analytical results, the purity of the water used in their laboratory operations is often the most important factor influencing the reliability of their analytical results.

Therefore, the use of water in a laboratory has changed from a utility to being a critical element in maintaining the integrity of an experimental result.

When Water Becomes the Hidden Variable

Water that is used in lab analyses is assigned controlled variables; however, there is a good chance that the water being used contains uncontrolled variables and has an impact on the experimental workflow, which may include things like dissolved organic compounds (DOC), endotoxins, trace metals, microorganisms, and their by-products.  Impurities can therefore cause reagents to be compromised, chemical reactions to change, and/or noise to be introduced into analyses.  

Trace ionic contamination can interfere with conductivity readings and baseline chromatography, while organic carbon impurities may interfere with mass spectrometry and/or molecular assays. Additionally, endotoxins or other microbial contaminants may compromise cell growth systems, creating results that are reported as a result of experiments that are not true results.

These effects can be very subtle, but they also accrue over time. Minimal changes in water purity (all things being equal) can result in decreased sensitivity on analytical instruments, inconsistencies in the performance of assays and unpredictable variability between laboratories attempting to reproduce each other’s results.

With scientific reproducibility coming under close examination, the purity of the water being used within experimental systems becomes an extremely important element that connects the creation of data to the credibility of that data.

Precision Science Requires Precision Water

Due to the growth of both complex and innovative research in life sciences as well as pharmaceuticals, the need for ultrapure water systems is on the rise. In addition, increased investment in biologics, advanced therapeutics, and precision medicine has resulted in an upsurge in biopharmaceutical R&D. For both research laboratories and quality control facilities in the pharmaceutical industry, ultrapure water with 18.2 MΩ·cm resistivity is required for use. The quality of water supplied (as evidenced by the TOC level of less than or equal to 1 part per billion) is also critical to provide the researcher with accurate readings for their instrumentation.

In life science research, ultrapure water is necessary for all non-pharmaceutical research applications. Accurate signal detection from low-level signals obtained through instruments used in many of these areas depends on the quality of ultrapure water supplied. The quality of the water determines whether the instruments will measure the true signal or if they are measuring an artifact caused by contamination from unknown sources.

Infrastructure, Monitoring, and the Rise of Intelligent Purification

Laboratories are changing the way they manage water quality, moving to a more dynamic monitoring system instead of a static purification process as analytical technologies progress and laboratory operations develop.

Recent data show that more than 60% of new laboratory purification systems installed this year use multi-stage technologies (like RO, DI, UF, and UV Oxidation) – which produce consistent levels of purity – and also use real-time digital readings for parameters (like resistivity, conductivity, and microbial load).

This shift reflects a greater transformation of laboratory infrastructure from treating purification as a stand-alone activity to various water systems integrated into the laboratory workflow(s).

Continuous monitoring provides laboratories with the ability to identify deviations from production before they affect experimental results, enabling laboratories to ensure consistent results within instruments, laboratories, and across research facilities.

For many globally distributed research organisations, this capability is essential, as standardised water quality enables analytical methods to be transferred from site to site without introducing variability that could create inconsistencies in data comparisons.

Elevating Water Quality as a Strategic Laboratory Priority

As scientific research becomes more data-driven and the pressure of regulation increases, laboratories are no longer able to treat water as a passive element of the research process. Instead, water needs to be managed with the same level of attention as other laboratory supplies, such as reagents and instrumentation.

What does the future of laboratory water management look like? The next major wave of innovation in laboratory water management will be the integration of water management into digital laboratory infrastructures. This will provide laboratories with the tools to move beyond quality control to quality assurance.

The quality of laboratory results depends not only on the quality of instrumentation and the skill of the researcher, but also on the quality of the fundamental inputs to the research process. At the bottom of this pyramid of quality are those inputs that are common to every research process. Water, as the most universal and possibly most important of these, stands at the bottom of the pyramid of quality. Ensuring the quality of water is not simply a requirement of the research process; it is a requirement of quality itself.