Agar Embedding
Agar Embedding - Related Videos
05:40
Preparation of Agar Bead Embedded Mycobacterium abscessus to Inoculate Immunocompetent Mice Intratracheally
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Cited by 3 •
2025
Mice are generally resistant to infections by Mycobacterium abscessus, which complicates the discovery and development of much-needed antibiotics against pulmonary infections. Here, we describe a method of inoculum preparation and intratracheal infection that was shown to deliver sustained infection in immunocompetent mice.
02:15
Subculturing Sulfite-Reducing Anaerobic Bacteria from an Agar Culture
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2025
Source: Anwar, Z., et al. Enrichment and Detection of Clostridium perfringens Toxinotypes in Retail Food Samples. J. Vis. Exp. (2019).In this video, sulfite-reducing bacteria are cultured in a sulfite-containing agar medium, where they grow anaerobically and reduce sulfite to hydrogen sulfide, forming black precipitates with iron ions. Black colonies are isolated from the agar depth using aseptic techniques and transferred to fresh medium for continued anaerobic incubation.
09:04
Yeast Colony Embedding Method
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Cited by 7 •
2011
A method for embedding yeast colonies allowing sectioning for light and electron microscopy. This protocol allows determination of the distribution of sporulated cells and pseudohyphal cells within colonies providing a new tool toward understanding the organization of cell types within a fungal community.
04:36
Assay for Adhesion and Agar Invasion in S. cerevisiae
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Cited by 17 •
2006
We describe a qualitative assay for yeast adhesion and agar invasion as a measure of invasive and pseudohyphal differentiation. This simple assay can be used to assess the invasive phenotype of various mutants as well as the effects environmental cues and signaling pathways on yeast differentiation.
03:37
Assessing the Antimicrobial Activity of Nisin Variants Using an Agar Well Diffusion Assay
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2025
Source: Nickling, J. H., et.al. Antimicrobial Peptides Produced by Selective Pressure Incorporation of Non-canonical Amino Acids. J. Vis. Exp. (2018)This video demonstrates an agar well diffusion assay used to evaluate the antimicrobial activity of nisin variants. It shows how Lactococcus lactis expressing the membrane-bound peptidase NisP activates nisin precursors produced in E. coli, resulting in growth inhibition halos. The size of these halos reflects the bioactivity of each nisin variant.
FAQs
The solidified agar matrix provides physical support around the specimen during handling, dehydration, paraffin embedding, and sectioning. This support reduces the likelihood that fragile material will fragment, become distorted, or be lost. By maintaining a stable block, the technique makes delicate samples easier to process while preserving more of the material needed for later microscopic examination.
Positioning the specimen before the agar solidifies helps establish a consistent alignment within the block. That alignment can improve sectioning and help preserve anatomical relationships that might otherwise be disrupted during processing. For irregular specimens or samples containing several fragments, careful orientation supports clearer interpretation because the resulting sections are more likely to represent the intended spatial arrangement.
Agar can surround fragments that are difficult to handle individually and hold them together as one supported block. This reduces the chance that small pieces will separate, shift, or disappear during later preparation. The approach is therefore especially valuable when maintaining the relative placement of several fragments or preserving the form of an irregular sample is important for histological analysis.
The specimen is first positioned in molten agar, with its desired orientation established before the matrix sets. Cooling then allows the agar to solidify around the biological material and form a stable block. That block can proceed through dehydration, paraffin embedding, and sectioning, providing a supported sample for microscopy preparation rather than requiring the specimen to be handled alone.
Researchers may select this approach when specimens are delicate, irregularly shaped, or present as multiple small tissue fragments. These characteristics make samples more vulnerable to fragmentation, distortion, or loss during routine preparation. Supporting them in agar improves handling and alignment before histological processing, making the method relevant when reliable preservation of sample structure is a priority.
Consistent agar support can produce clearer sections by keeping the specimen stable and better aligned during processing and sectioning. It also helps preserve anatomical relationships within the sample, which supports more dependable microscopic observations. The resulting improvement is not simply easier handling; it can strengthen confidence that visible features reflect the specimen’s organization rather than preparation-related displacement or damage.