Colorimetric Detection
Colorimetric Detection - Related Videos
03:05
Colorimetric Detection of Cortex Degradation During Bacterial Spore Germination
0 Views •
2025
Source: Francis, M. B., et al. Detecting Cortex Fragments During Bacterial Spore Germination. J. Vis. Exp. (2016).This video demonstrates a colorimetric method to detect cortex degradation during bacterial spore germination by measuring the release of reducing sugars over time. Using N-acetylglucosamine standards and time-point samples, the assay quantifies sugar concentration through a purple chromogenic reaction, indicating the extent of cortex hydrolysis.
10:05
Colorimetric Detection of Bacteria Using Litmus Test
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Cited by 5 •
2016
We describe a protocol for colorimetric detection of E. coli using a modified litmus test that takes advantage of an RNA-cleaving DNAzyme, urease, and magnetic beads.
09:32
ampliPHOX Colorimetric Detection on a DNA Microarray for Influenza
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Cited by 4 •
2011
ampliPHOX colorimetric detection technology is presented as an inexpensive alternative to fluorescence detection for microarrays. Based on photopolymerization, ampliPHOX produces solid polymer spots visible to the naked eye in just a few minutes. Results are then imaged and automatically interpreted with a simple yet powerful software package.
03:08
Colorimetric Assay for Quantification of Lactate in Test Samples
0 Views •
2025
This video describes a colorimetric assay for lactate measurement in cell lysates by using the lactate dehydrogenase enzyme. This enzyme converts lactate into pyruvate, along with the conversion of NAD to NADH that reacts with tetrazolium dyes and gives a colored product that can be measured spectrophotometrically to quantitate the lactate.
03:04
Colorimetric Detection of a Bacterial Biomarker Using a Modified Litmus Test
0 Views •
2025
This video demonstrates a colorimetric E. coli detection method, involving an E. coli biomarker activating a DNAzyme, leading to cleavage of RNA linkage and detachment of a DNAzyme-urease conjugate. A subsequent colorimetric assay detects the E. coli biomarker through ammonia-induced pH changes.
FAQs
The chromogenic reagent or substrate provides the chemical basis for the visible signal. When the target analyte or enzyme reacts with it, the reaction produces a colored compound that can be assessed instead of relying on an invisible biological event. Selecting the reagent or substrate therefore links the assay's chemistry to the substance or activity being investigated.
Two readout options are supported. A researcher can estimate the color by eye when a straightforward qualitative assessment is sufficient, or measure absorbance with a spectrophotometer when a more instrument-based result is needed. This distinction lets the same general approach serve simple teaching or testing settings as well as quantitative biological research.
Color intensity indicates that the reaction has generated a detectable colored compound, and its magnitude can be estimated visually or recorded as absorbance. Interpretation depends on what the assay targets: the signal may be associated with an analyte, such as a protein or metabolite, or with enzyme activity. The measurement connects an observable signal to a biological target.
The approach is broad because its targets can include proteins, nucleic acids, metabolites, and enzyme activity. Biological material may come from cells, tissues, or biological fluids, so the method is not restricted to one sample type or one molecular class. This range makes it useful for examining both molecular components and biochemical activity in biology.
First, the sample is brought into contact with a chromogenic reagent or substrate selected for the target analyte or enzyme activity. The reaction then produces its colored compound, after which the result is assessed visually or by measuring absorbance with a spectrophotometer. The workflow converts a biological reaction into a recordable assay signal.
Microplate compatibility supports the use of colorimetric detection in organized biological assays without changing its basic readout options. Researchers can still estimate color visually or measure absorbance, while the format fits applications in teaching laboratories and quantitative research. Along with the method's low cost and simplicity, this compatibility helps explain its broad practical value.
Its simplicity and low cost make the approach accessible in teaching laboratories, where straightforward assay readouts are valuable. The same practical features support clinical testing and environmental biology, while spectrophotometric absorbance measurements extend it to quantitative research. Thus, colorimetric detection can accommodate both accessible testing and more measurement-focused biological studies.