Tricks, Treats & Toxicology: The Science of Detecting What’s in a Sample
In toxicology, appearances can be deceiving. A sample that looks ordinary may contain tiny amounts of drugs, chemicals, metabolites, or other compounds that can reveal important information about exposure. Finding those compounds requires more than sophisticated analytical instruments, it starts with careful sample preparation.
Toxicology laboratories analyze biological samples such as blood, urine, saliva, and tissue to identify and measure substances that may be present. Depending on the application, researchers may be looking for pharmaceuticals, environmental contaminants, toxins, or the metabolites produced as the body processes these substances.
Before a sample ever reaches an analytical instrument, however, it typically goes through several preparation steps.
Preparing the Sample
Biological samples are complex mixtures containing proteins, salts, cells, and countless other compounds. Researchers often need to isolate, dilute, or otherwise prepare the substances they want to measure while minimizing anything that could interfere with the analysis.
Accurate liquid handling is critical throughout this process. BRAND® Transferpette® pipettes and pipette tips can support precise sample and reagent transfers, while BRAND® microplates and Deep-well plates provide options for preparing and processing multiple samples in parallel.
When the same volume must be dispensed repeatedly, such as when adding reagents across a series of tubes or wells, a BRAND® HandyStep® repeating pipette can help make repetitive dispensing more efficient.
Creating a Point of Comparison
Detecting a substance is only part of the challenge. Toxicologists often need to determine how much of it is present.
To do that, laboratories can prepare standards containing known concentrations of the compound being measured. A series of standards may be produced through serial dilution, in which a solution is diluted step by step to create progressively lower concentrations.
These standards establish a reference that can be compared with unknown samples during analysis. Because an error introduced during one dilution can affect subsequent concentrations, accurate and consistent pipetting is especially important when preparing a dilution series.
Contamination Can Change the Story
When scientists are searching for substances at very low concentrations, even a small amount of unintended material can potentially interfere with results.
Good laboratory technique therefore extends beyond the analytical instrument itself. Using appropriate pipette tips, changing tips between samples, properly sealing plates, maintaining clean workspaces, and carefully handling reagents can all help reduce the possibility of cross-contamination.
BRAND® microplate sealing films and foils can also help protect samples during storage, incubation, or processing and reduce the risk of contamination or evaporation.
From Sample to Answer
Once preparation is complete, samples can move on to analytical techniques such as chromatography, mass spectrometry, or other methods capable of separating and detecting individual compounds.
These instruments may provide the final measurement, but the quality of that answer depends heavily on everything that happened beforehand. Careful sample preparation, accurate dilution, consistent liquid handling, and contamination control all contribute to reliable results.
This Halloween, the real trick in toxicology isn't finding something mysterious hiding in a sample. It's making sure scientists have prepared that sample carefully enough to reveal exactly what's there.