Let's talk about lab water
Let's talk about lab water
Pure water plays a pivotal role in almost every life science experiment, diagnostic test or chemical reaction. It’s so important, there’s even a high impact journal dedicated to reporting on new water-based research and purification methods. Sadly, lab water still rarely gets the attention it deserves.
Without pure water, very few experiments, tests or reactions would be possible. Thanks to its favorable chemical and physical properties, water is often considered the ‘universal solvent’ as it dissolves more substances than any other liquid. Perhaps even more importantly, many biochemical reactions will only take place within aqueous solutions.
One potential limitation of water is that it is a weak eluent and a poor solvent of most organic compounds, due to it being highly polar at ambient temperatures. However, superheated water at 200°C has similar properties to typical organic solvents such as methanol, so it can be used to dissolve many organic compounds. This adds even more credibility to water’s status as the universal solvent and means you can use it in a wider range of applications, such as separation and extraction science. Even better, water is cheaper, less flammable and more environmentally friendly than most organic solvents – more great reasons why water is an essential reagent in the lab!
Some of the most interesting science being carried out at the moment pushes the boundaries of analytical sensitivity. Techniques such as inductively-coupled plasma mass spectrometry (ICP-MS), thermal ionization mass spectrometry (TIMS) and ICP atomic emission spectrometry (ICP-AES) allow researchers to explore biological and chemical systems in more detail and at greater resolution than ever before, including being able to detect the presence of chemicals and factors at trace (<100 ppm) and ultra-trace (<1 ppm) concentrations.
As an example, such sensitivity allows us to detect low expression biomarkers so that we can better diagnose and treat patients, helping to turn the promise of personalized medicine into a reality. High sensitivity analysis is also highly useful when working with environmental samples, so that researchers can better track global climate and environmental change.
In order to achieve ultra-sensitivity, pure water is essential. It provides you with more control over the type of substances dissolved and the exact concentration of your solute, leading to higher experimental reproducibility. After all, you wouldn’t put the wrong fuel into your sports car and expect the desired result either.
Most molecular biology also relies on assay sensitivity to produce reproducible and reliable results. For example, the generation of DNA and RNA sequencing data can often be challenging, with double sequence readout, failed sequencing reactions and large dye blobs in the sequence being more common than you might imagine. Many of these types of errors are characteristic of sample contamination and/or a poor water quality, as excess salts and contaminants can greatly hinder your ability to obtain good quality sequence data.
As you can see, contamination can be a real confounding factor in many experimental procedures, especially those relying on high detection sensitivity. In the next installment, we take a look at how science moves along incrementally – adding one small experiment on top of another – and why focusing on these baby steps is so important for realizing your larger research goals.
Baby steps in science are made through daily experiments that produce consistent, reliable results. They are the building blocks that lay the foundations for great scientific breakthroughs. As such, a large part of your time and focus in the lab is spent on getting these experiments functioning effectively.
For example, when Andrew Z. Fire and Craig C. Mello were working to understand the mechanism of RNA interference (research for which they shared the Nobel Prize in Physiology or Medicine in 2006) the day-to-day activities of their studies would have involved cloning, RNA synthesis and dsRNA injection to name but a few. It was their dedication and perseverance, diligently and accurately repeating all of these steps while carefully altering one variable at a time that ultimately led to the development of one of biology’s most powerful techniques. I expect that similar daily grind was behind the successful cloning of GFP from jellyfish, which is now the biologist’s favorite fluorescent marker protein.
One ‘simple’ technique behind such pioneering studies is PCR, an approach so routine and well understood, that you wouldn’t expect to have to troubleshoot it very often. However, the process can often take several hours to complete, so any time spent trying to identify problems with your reaction could take days or even weeks to fix. These are frustrating challenges to have when you are trying to make ground-breaking discoveries!
Like most reactions in the lab, PCR is sensitive to contamination by factors such as extraneous DNA, enzymes and ions, so it’s worth considering that the right level of water purity will be essential to your success. This is also true of almost all lab techniques you can imagine, from cloning, Western blot and mass spectrometry, through to chromatography, DNA extraction and in situ hybridization – even techniques on a much larger scale, such as histology, can be affected by water contamination. If you can get your daily experiments working correctly, then you’ll be well on your way to discovering something new about how the world works (and who knows, it may even land you a Nobel Prize in the future!).
Achieving consistently accurate results can be testing in itself. However, it’s even more important when you are actually carrying out testing (of patient samples, for example). In this penultimate episode in our unsung hero series, we turn our attention to the importance of assay accuracy when the lives of patients may be at stake.
The benefits of pure water don’t stop at research – if you work in a diagnostic lab then the lives of patients may depend on your work. Many water contaminants can affect diagnostic results, for example:
Total calcium analysis is used to identify diseases such as epilepsy, chronic liver disease and intestinal malabsorption. The reliability of the data obtained can be significantly affected by oxalate, sulphate and calcium contamination.
Alkaline phosphatase is an enzyme present inside all body cells – tests to assay its function are used to diagnose bone, liver, gallbladder, parathyroid gland and bile duct disease, as well as Vitamin D deficiency. However, the results of these tests are negatively influenced by fluoride, phosphate, zinc, manganese, arsenate, EDTA, bacteria and/or endotoxins present in the sample and/or reagents being used.
Iron analysis is used to investigate a wide range of problems, from depression, joint pain and irregular heartbeat to liver trouble, diabetes and infertility. However, the reliability of iron quantification in blood samples is reduced by the presence of EDTA, oxalate and fluoride.
These are just a few examples, but as you can see, using a reliable pure water supply is essential for obtaining informative results – and for helping doctors select the right treatments for patients.
Regardless of the type of lab you work in, getting your assays, reactions or tests to work correctly first time saves you time and money – and that means using the best possible water supply.
A consistent, high quality water supply will:
It’s estimated that labs use over 5 times more water than similarly sized office buildings and enough to fill over 14 Olympic-sized swimming pools over the course of a year, so water really is the fuel that drives your research. It’s quality really can make a difference: if you consider, for example, that ~70% of HPLC performance problems are thought to be directly attributable to water quality, you quickly begin to realize that water purity is something that we as scientists should be paying more attention to. Whether you are attempting to probe deeper into biology than ever before or just trying to generate accurate results from your tried and tested assays, using reliable, high quality water of the right purity is essential to your success.