Matrix Matching
Matrix Matching - Related Videos
01:17
Sign Test for Matched Pairs
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2025
The sign test for matched pairs offers a robust method for comparing two paired samples, often for the effects of an intervention in one of them. This method is very useful in situations where the underlying distribution of the data is unknown. The test compares two related samples—often pre- and post-treatment measurements on the same subjects—to determine if there are significant differences in their median values. To conduct the sign test, we first calculate the differences in value between...
09:38
Dithranol as a Matrix for Matrix Assisted Laser Desorption/Ionization Imaging on a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer
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Cited by 3 •
2013
Dithranol (DT; 1,8-dihydroxy-9,10-dihydroanthracen-9-one) has previously been reported as a MALDI matrix for tissue imaging of small molecules; protocols for the use of DT for the MALDI imaging of endogenous lipids on the surface of tissue sections by positive-ion MALDI-MS on an ultrahigh-resolution quadrupole-FTICR instrument are provided here.
01:09
Wilcoxon Signed-Ranks Test for Matched Pairs
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2025
The Wilcoxon signed-rank test for matched pairs evaluates the null hypothesis by combining the ranks of differences with their signs. It essentially tests whether the median of the differences in a population of matched pairs is zero. Since the test incorporates more information than the sign test, it generally yields more trustable conclusions. This test also does not require the data to follow a normal distribution, but two conditions must be met for it to be applicable: (1) the data must...
11:35
Fabrication of an Expandable Brain Matrix Customizable Across Developmental Stages
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2026
An innovative method to build expandable brain matrices to cut either coronal or sagittal slices is described for application to neonatal piglets. This budget-friendly approach utilizes acrylic plates carved using templates from agarose gel brain molding, applies to multiple species, and allows for expansion to accommodate brain growth.
08:06
Testing for Metacognitive Responding Using an Odor-based Delayed Match-to-Sample Test in Rats
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Cited by 4 •
2018
This protocol describes a method for investigating the possibility of metamemory, or memory awareness, in rodents. The odor-based delayed-matching-to-sample paradigm is a novel, ecologically-relevant behavioral test useful for determining the extent to which rodents can adaptively respond based on cognitively monitoring the strength of their memory states.
FAQs
It reduces the influence of coexisting substances on several stages of measurement. Proteins, salts, lipids, and other matrix components can change analyte recovery, signal intensity, ionization, or detection. Preparing standards in a comparable medium allows the calibration response to reflect those influences, helping measured concentrations more closely represent the analyte amount in the biological specimen.
The relevant components depend on the specimen and assay, but biological matrices may contain proteins, salts, lipids, or other coexisting substances. Their combined composition matters because even substances that are not the target analyte can alter analytical response. Standards should therefore reproduce the important features of the sample medium rather than only the analyte itself.
A calibration response can change when the surrounding sample composition changes. Matching standards to the biological material helps account for those composition-dependent effects, making measurements more accurate and comparable. This is particularly important when results from blood, plasma, urine, tissue extracts, or cell lysates must be interpreted alongside one another or evaluated across experiments.
First, identify the biological specimen and the matrix components likely to influence measurement. Then prepare calibration standards in a sample medium with a similar composition, incorporating the analyte at the required calibration levels. The resulting standards can be analyzed with the specimens so the calibration relationship reflects the matrix conditions present during measurement.
The strategy can support calibration in chromatography, mass spectrometry, spectrophotometry, and immunoassays. Its value is not limited to one detection principle: it helps address matrix-related changes in recovery, signal intensity, ionization, or detection. The analytes may include drugs, metabolites, nucleic acids, or biomarkers measured in complex biological samples.
Matrix matching is most useful when the target analyte is measured in complex specimens rather than a simple prepared solution. Applications include quantifying drugs or metabolites in blood, plasma, and urine, as well as measuring nucleic acids or biomarkers in tissue extracts and cell lysates. It provides calibration conditions that better reflect the biological material under study.