Onion Cell Preparation
Onion Cell Preparation - Related Videos
10:39
Bimolecular Fluorescence Complementation (BiFC) Assay for Protein-Protein Interaction in Onion Cells Using the Helios Gene Gun
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Cited by 18 •
2010
This article illustrates how to properly use the BioRad Helios Gene Gun to introduce plasmid DNA into onion epidermal cells and how to test for protein-protein interactions in onion cells based on the principle of Bimolecular Fluorescence Complementation...
09:39
Preparation of Drosophila S2 cells for Light Microscopy
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Cited by 24 •
2010
Drosophila Schneider (S2) cells are an increasingly popular system for the discovery and functional analysis of genes. Our goal is to describe some of the microscopic techniques that make S2 cells such an increasingly important experimental system.
06:20
Cell Division - Student Protocol
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2019
Observing the Cell Cycle in a Root Tip ExpandHypotheses: The experimental hypothesis is that in root tips slices that have been treated with nocodazole, a chemical that interferes with microtubular polymerization, all of the cells will be arrested at the same stage of the cell cycle and that in untreated onion tip slices all of the different stages of the cell cycle will be visualized. The null hypothesis is that there will be no differences in mitosis between the two groups and that different...
07:42
Chromosome Preparation From Cultured Cells
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Cited by 146 •
2014
Chromosomes can be isolated from live cells such as lymphocytes or skin fibroblasts, and from organisms including humans or mice. These chromosome preparations can be further utilized for routine G-banding and molecular cytogenetic procedures such as fluorescence in situ hybridization (FISH), comparative genomic hybridization (CGH), and spectral karyotyping (SKY).
04:51
Cell Structure - Student Protocol
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2019
Visualizing Onion and Human Cells ExpandIn this experiment you will prepare different types of cells from a plant and animal, onion and human respectively, and then visualize them under a microscope. HYPOTHESES: The experimental hypothesis is that the cells will appear different in overall shape and membrane structure, but there will be some shared similar structures, like nuclei, in both cells. The null hypothesis of the experiment is that there will be no difference in structure between the...
FAQs
The inner epidermal layer provides a thin, relatively accessible sheet of cells that can be isolated and placed on a slide. Its thinness helps the microscope reveal organized cell structures rather than a thick mass of onion tissue. This choice makes the preparation practical for introductory observations of plant-cell organization and the relationship between cell structure and microscopy.
Staining increases contrast between cellular structures and the surrounding mounting medium, making features easier to distinguish under magnification. In an unstained preparation, boundaries or internal components may be less apparent. The improved contrast supports clearer observation of the nucleus, cell wall, and large vacuole, helping students connect visible patterns with basic plant-cell organization.
The mounting liquid holds the peeled epidermal layer against the slide and creates the immediate viewing environment for the cells. Because the preparation is observed through this mounted layer, the mounting condition can affect how clearly structures appear. Comparing observations under different mounting conditions can therefore introduce how preparation choices influence microscopic outcomes.
These structures are identified through their relative visibility and position within the organized epidermal cells. Cell walls outline adjacent cells, the large vacuoles occupy much of the cell interior, and staining can help make nuclei distinguishable. Observing these features together provides evidence of coordinated plant-cell organization rather than treating each structure as an isolated detail.
A typical workflow begins by peeling a thin inner epidermal layer from an onion and transferring it to a microscope slide. The layer is placed in a liquid mount, and staining may be used to increase contrast. After mounting, the specimen is viewed under magnification so its cell boundaries and internal structures can be examined.
This preparation can reveal patterns of plant-cell organization, including repeated cell boundaries and distinguishable internal features such as large vacuoles and nuclei. Those observations allow learners to connect cell theory with direct visual evidence. The exercise also provides practice with specimen mounting, staining, magnification, and interpreting how preparation conditions affect what can be seen.