Tissue Sampling Fraction
Tissue Sampling Fraction - Related Videos
11:17
A Simple Fractionated Extraction Method for the Comprehensive Analysis of Metabolites, Lipids, and Proteins from a Single Sample
0 Views •
Cited by 67 •
2017
A protocol for comprehensive extraction of lipids, metabolites and proteins from biological tissues using one sample is presented.
09:20
Proteomic Sample Preparation from Formalin Fixed and Paraffin Embedded Tissue
0 Views •
Cited by 50 •
2013
Archival formalin fixed and paraffin embedded (FFPE) clinical samples are valuable material for investigation of diseases. Here we demonstrate a sample preparation workflow allowing in-depth proteomic analysis of microdissected FFPE tissue.
10:09
Fractional Distillation
0 Views •
2023
Source: Laboratory of Dr. Nicholas Leadbeater — University of Connecticut Distillation is perhaps the most common laboratory technique employed by chemists for the purification of organic liquids. Compounds in a mixture with different boiling points separate into individual components when the mixture is carefully distilled. The two main types of distillation are "simple distillation" and "fractional distillation", and both are widely used in organic chemistry laboratories. Simple distillation...
08:48
Quantitation of γH2AX Foci in Tissue Samples
0 Views •
Cited by 7 •
2010
Quantitation of DNA double-strand breaks on the basis of γH2AX foci has become an invaluable tool, particularly in radiation biology, for the evaluation of tissue radiosensitivity and effects of radiation modifying compounds. Here we demonstrate the use of an immunofluorescence assay for quantitation of γH2AX foci in tissue samples.
02:08
A Hydrophobic Tissue Clearing Method for a Rat Brain Tissue Sample
0 Views •
2025
Source: Kirchner, K.N., et al., A Hydrophobic Tissue Clearing Method for Rat Brain Tissue. J. Vis. Exp. (2020).This video demonstrates the method of hydrophobic tissue clearing of a rat brain tissue sample. The sample is sequentially dehydrated in methanol, treated with a dichloromethane and methanol mixture to dissolve lipids and pigments, and transferred to dibenzyl ether for complete tissue clearing, enabling detailed imaging without thin sectioning.
FAQs
Representativeness depends on more than the numerical size of the fraction. A larger fraction can still mischaracterize an organism when the selected region differs from unsampled regions in molecular, chemical, histological, or physiological properties. Researchers therefore consider tissue heterogeneity and sampling location alongside the fraction, because uneven composition can introduce bias even when the calculation itself is accurate.
Sampling location changes how a tissue sampling fraction should be interpreted. If tissue properties vary within an organism, selecting material from one region may produce a fraction that is mathematically correct but biologically unrepresentative. Consistent location selection across specimens helps separate genuine biological differences from differences caused by where tissue was collected, strengthening comparisons and reducing location-related sampling bias.
The appropriate fraction depends on the analysis and the cost of collection. Destructive sampling removes material that cannot be returned to the organism, so researchers must balance sufficient coverage against preserving available tissue for other measurements or specimens. This decision is especially important when tissue quantity is limited or when several molecular, chemical, histological, or physiological analyses are planned.
To calculate tissue sampling fraction, researchers compare the sampled mass, volume, or number of tissue units with the corresponding total available amount. The numerator and denominator must describe the same type of quantity and tissue scope; otherwise, the resulting proportion can be misleading. Recording the collection location and method with the calculation also makes the value interpretable across specimens.
A practical workflow begins by identifying the total tissue available, selecting the regions and units to collect, and documenting the collection method. The sampled amount is then measured in mass, volume, or tissue units and compared with the matching total. Applying the same design across specimens supports consistent subsampling and makes differences in analytical results easier to evaluate.
Tissue sampling fraction helps researchers judge uncertainty in measurements derived from subsamples. When the sampled portion is small relative to a heterogeneous tissue supply, results may depend strongly on the selected material; increasing coverage or standardizing selection can improve confidence. This reasoning applies across molecular, chemical, histological, and physiological studies, where sample adequacy affects interpretation of the whole biological system.