Fingerprint Region
Fingerprint Region - Related Videos
01:03
IR Frequency Region: Fingerprint Region
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2024
IR spectra are divided into two main regions: the diagnostic region and the fingerprint region. The diagnostic region of the spectrum lies above 1500 cm−1. The absorptions resulting from single-bond vibrations of the N–H, C–H, and O–H stretch at higher wavenumbers and appear on the left side of the spectrum. The stretching absorptions of the C≡C and C≡N occur between 2100–2300 cm−1. In contrast, those arising from stretching absorptions of the C=O, C=N, and C=C occur between 1600–1850 cm−1. The...
12:02
Automated Modular High Throughput Exopolysaccharide Screening Platform Coupled with Highly Sensitive Carbohydrate Fingerprint Analysis
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Cited by 18 •
2016
We present an automated modular high-throughput-method for the identification and characterization of microbial exopolysaccharides in small scale. This method combines a fast preselection to analyze the total amount of secreted polysaccharides with a detailed carbohydrate fingerprint to enable the fast screening of newly isolated bacterial strains or entire strain collections.
09:39
DNA Fingerprinting of Mycobacterium leprae Strains Using Variable Number Tandem Repeat (VNTR) - Fragment Length Analysis (FLA)
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Cited by 9 •
2011
Leprosy, caused by Mycobacterium leprae, is still endemic in many places. In order to learn about the spread and mode of transmission of leprosy, it is important to determine which strain of M. leprae has infected a patient. Variable numbers of tandem repeats (VNTR) typing is one such method.
08:35
Application of DNA Fingerprinting using the D1S80 Locus in Lab Classes
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Cited by 2 •
2021
Here we describe a simple protocol to generate DNA fingerprinting profiles by amplifying the VNTR locus D1S80 from epithelial cell DNA.
02:40
The Eukaryotic Promoter Region
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2020
The eukaryotic promoter region is a segment of DNA located upstream of a gene. It contains an RNA polymerase binding site, a transcription start site, and several cis-regulatory sequences. The proximal promoter region is located in the vicinity of the gene and has cis-regulatory sequences and the core promoter. The core promoter is the binding site for RNA polymerase and is usually located between -35 and +35 nucleotides from the transcription start site. The distal promoter regions are...
FAQs
Its diagnostic value comes from the combined pattern of many absorption bands rather than from one isolated signal. Molecular stretching and bending vibrations contribute bands at different positions and intensities, creating a complex spectral pattern related to the compound’s structure. Comparing this overall pattern provides stronger identification evidence than relying on one functional-group absorption alone.
Bond stretching and bending vibrations absorb infrared radiation at positions and intensities that depend on the molecule’s structure. Because compounds have different structural arrangements, the combined vibrational responses form different patterns in this region. Those differences allow chemists to distinguish substances that may show similar functional-group absorptions elsewhere in the IR spectrum.
Functional-group analysis indicates which broad structural features may be present, while the fingerprint region adds a detailed pattern for comparing the entire compound. Using both types of information improves interpretation: functional groups support an initial structural assessment, and the fingerprint pattern helps confirm identity or distinguish compounds with similar functional groups.
Chemists compare the unknown sample’s fingerprint-region pattern with spectra from reference compounds. Agreement in the combined positions and intensities of the absorption bands supports the proposed identity, whereas a different pattern suggests that the substances are not the same. This comparison is especially useful when functional-group information alone cannot distinguish closely related materials.
The workflow begins with obtaining the sample’s IR spectrum and examining the portion containing the fingerprint pattern. Chemists then compare that pattern with an appropriate reference spectrum, considering the combined band positions and intensities rather than one feature alone. The comparison can support compound identification, distinguish substances, or contribute to sample-composition assessment.
This analysis is useful when researchers need to characterize an unknown material, verify a compound’s identity, or distinguish samples with similar functional groups. It also supports quality control by helping assess sample composition and can aid reaction monitoring by comparing spectral patterns as chemical materials change. These applications make it a complement to broader IR interpretation.