Biological Sample Preparation
Biological Sample Preparation - Related Videos
08:04
Preparation and Observation of Thick Biological Samples by Scanning Transmission Electron Tomography
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Cited by 9 •
2017
This report describes a sample preparation protocol and specific imaging conditions for performing scanning transmission electron tomography of thick biological specimens.
09:02
SEM Imaging of Biological Samples
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2023
Source: Peiman Shahbeigi-Roodposhti and Sina Shahbazmohamadi, Biomedical Engineering Department, University of Connecticut, Storrs, Connecticut A scanning electron microscope (SEM) is an instrument that uses an electron beam to nondestructively image and characterize conductive materials in a vacuum. As an analogy, an electron beam is to the SEM as light is to the optical microscope. The difference is that the electron microscope yields images of much higher resolution and magnification. The...
04:17
Chemical Drying: Biological Sample Preparation for Scanning Electron Microscopy (SEM)
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2023
Scanning electron microscopy (SEM) is a powerful tool to image—primarily—the surface features of a biological sample. Proper sample preparation, however, is critical to obtaining quality images. This video focuses on the dehydration and drying steps of preparing intact adult Drosophila for SEM.
01:10
X-ray Diffraction of Biological Samples
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2023
X-ray diffraction or XRD is an analytical tool that utilizes X-rays to study ordered structures such as crystalline organic and inorganic samples, polycrystalline materials, proteins, carbohydrates, and drugs. According to Bragg's law, when X-rays strike the sample positioned on a stage, the rays are scattered by the electron clouds around the sample atoms. The X-ray diffraction or scattering is caused by constructive interference of the X-ray waves that reflect off the internal crystal...
06:00
Biological Samples Preparation for Speciation at Cryogenic Temperature using High-Resolution X-Ray Absorption Spectroscopy
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Cited by 3 •
2022
This protocol presents a detailed procedure to prepare biological cryosamples for synchrotron-based X-ray absorption spectroscopy experiments. We describe all the steps required to optimize sample preparation and cryopreservation with examples of the protocol with cancer and phytoplankton cells. This method provides a universal standard of sample cryo-preparation.
FAQs
Solvent choice and pH help determine which target compounds move out of a biological matrix and remain chemically stable. Their effects also influence how many interfering substances are extracted at the same time. Controlling these conditions improves the selectivity of the prepared sample and supports more reliable identification or quantification during subsequent chemical analysis.
Homogenization makes the biological material more uniform, helping distribute target compounds throughout the sample. Filtration or centrifugation then separates unwanted material from the prepared liquid or extract. Together, these operations reduce physical heterogeneity and remove potential interferences, giving chromatography, spectroscopy, mass spectrometry, or biochemical assays a more consistent sample to measure.
Handling time, temperature, pH, and solvent conditions can affect whether analytes remain intact during preparation. Poor control may alter the compounds before measurement, reducing the accuracy of identification or quantification. Careful handling therefore preserves the original chemical composition as much as possible and makes results more representative of the biological material collected.
Biological materials contain complex mixtures that can interfere with measurement of a target compound. Extraction, filtration, centrifugation, concentration, or purification can reduce those unwanted components while retaining the analyte of interest. A cleaner prepared sample helps analytical methods distinguish target signals more effectively, supporting dependable results for metabolites, proteins, drugs, contaminants, and other compounds.
A practical workflow begins with collection of the tissue, cell, fluid, or other material, followed by homogenization when uniformity is needed. The target compounds are then extracted, and the mixture may undergo filtration or centrifugation. Depending on the analysis, concentration or purification can follow before the sample is introduced into the selected chemical measurement method.
Researchers use it when a biological matrix must be made compatible with a chemical analysis and when target compounds need separation from interfering substances. Preparation can isolate or concentrate metabolites, proteins, drugs, contaminants, or related analytes before chromatography or mass spectrometry. This improves the usefulness of downstream measurements by supporting clearer identification and more dependable quantification.
Prepared samples can support both identification and quantification of compounds present in complex biological materials. Depending on the analytical platform, the resulting measurements may concern metabolites, proteins, drugs, contaminants, or other chemical constituents. In chemistry, this information enables biological samples to be examined with chromatography, mass spectrometry, spectroscopy, or biochemical assays.