Laboratory Methods
Laboratory Methods - Related Videos
18:00
Aseptic Laboratory Techniques: Plating Methods
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Cited by 490 •
2012
When working with media and reagents used to culture microorganisms, aseptic technique must be practiced to ensure contamination is minimized. A variety of plating methods are routinely used to isolate, propagate, or enumerate bacteria and phage, all of which incorporate procedures that maintain the sterility of experimental materials.
06:49
A Laboratory Method to Measure Contagious Yawning in Rats
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Cited by 1 •
2019
The method described here aims to obtain yawn contagion curves in pairs of familiar or unfamiliar male rats. Cages with holes separated by either clear or opaque partitions with (or without) holes are used to detect whether visual, olfactory, or both types of sensory cues can stimulate yawn contagion.
06:54
Methods for Presenting Real-world Objects Under Controlled Laboratory Conditions
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Cited by 10 •
2019
We describe methods for presenting real-world objects and matched images of the same objects under tightly-controlled experimental conditions. The methods are described in the context of a decision-making task, but the same real-world approach can be extended to other cognitive domains such as perception, attention, and memory.
07:27
Making Solutions in the Laboratory
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2023
The ability to successfully make solutions is a basic laboratory skill performed in virtually all biological and chemical experiments. A solution is a homogenous mixture of solute dissolved in bulk liquid known as the solvent. Solutions can be described by their solute concentration, a measure of how much solute is present per unit of solution. In this video, a step-by-step procedure for how to make a water-based, or aqueous, solution for biological applications is presented. The video...
06:19
Decontamination for Laboratory Biosafety
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2023
Robert M. Rioux and Zhifeng Chen, Pennsylvania State University, University Park, PA Decontamination is essential for laboratory biosafety, as the accumulation of microbial contamination in the laboratory can lead to the transmission of disease. The degree of decontamination can be classified as either disinfection or sterilization. Disinfection aims to eliminate all pathogenic microorganisms, with the exception of bacterial spores on lab surfaces or equipment. Sterilization, on the other hand,...
FAQs
Calibration links an instrument’s response to known reference values, allowing measured signals to be interpreted quantitatively. Without this comparison, results may be difficult to evaluate or compare across samples. In environmental analysis, calibration supports more dependable estimates of pollutant concentrations, nutrient levels, and physical or chemical properties, while helping identify deviations that could affect scientific or regulatory conclusions.
Preservation and preparation help maintain the sample’s relevant characteristics and make it suitable for measurement or testing. These steps can also reduce contamination and other sources of bias introduced before analysis. Their quality directly affects whether results represent the original water, soil, air, or biological material and whether subsequent measurements can support credible environmental interpretation.
Instrument-based analyses provide measurements of chemical or physical properties, whereas culture-based testing examines microorganisms through growth-based procedures. The choice depends on what the sample must reveal, such as pollutant or nutrient quantities versus microbial presence or characteristics. Using the appropriate testing approach helps align the evidence collected with the environmental question under investigation.
Quality-control checks are used to detect contamination, bias, and measurement error during laboratory work. They complement calibration and help determine whether a result is sufficiently reliable for interpretation. When quality-control findings reveal problems, the data may require closer review before supporting contamination assessments, ecosystem monitoring, regulatory compliance, or environmental risk evaluation.
A typical workflow moves from sample collection to preservation, preparation, measurement or testing, and interpretation. Calibration against known standards and quality-control checks are integrated into this sequence rather than treated as optional final steps. Organizing the work in this order helps connect the original environmental material to results that can be evaluated consistently.
Laboratory Methods generate evidence about pollutants, nutrients, microorganisms, and physical or chemical properties in water, soil, air, and biological materials. Those measurements can be used to assess contamination, monitor ecosystems, demonstrate regulatory compliance, evaluate risks, and guide environmental protection strategies. Their value depends on producing results that are sufficiently controlled and interpretable for the decision involved.