Agar

This agar contains cefsulodin, irgasan, and novobiocin, and the differential qualities derive from the ability of Y. enterocolitica to produce acrid from mannitol, resulting in a deep cherry-red heart on the Yersinia colonies, which has been described every bit a balderdash'southward eye appearance.

From: Encyclopedia of Nutrient Microbiology (Second Edition) , 2014

Auxiliary Materials

Chiayi Shen undefined , in Phillips' Science of Dental Materials , 2022

Making Agar Impression

This process requires a 3-compartment conditioning unit (Figure 13-xiii ) for the agar tray fabric that allows liquefaction, storage, and tempering; the agar syringe material is used only in the liquefaction and storage compartments.

The offset step in impression making is to liquefy the hydrocolloid gel in the tube in boiling water at 100 °C. The tube is and then placed in a storage bathroom at 65 °C to retain the sol condition until it is needed. For the immediate preparation step, the impression tray is filled with hydrocolloid sol from the tube taken from the storage bath, a gauze pad is placed over the superlative of the tray material, and the tray is placed in the tempering compartment (at about 45 °C). The tempering time is 3 to 10 minutes, just sufficient to ensure that all the material has reached a low temperature of 55 °C or less. In any example, the loaded tray should never be left in this bathroom for more than 10 minutes because partial gelation tin can occur, thereby making the material unusable.

Just before tempering of the tray material is completed, the syringe cloth is taken direct from the storage compartment and applied to the prepared teeth. The syringe fabric is never tempered because it must exist maintained in a fluid state to enhance adaptation to the tissues. Normally, the temperature of the syringe textile is cooled sufficiently as information technology is extruded, and then information technology is comfy for the patient. The syringe material is first practical to the base of operations of the training; then the remainder of the prepared molar is covered. The tip of the syringe is held close to the tooth, and it remains embedded below the surface of the syringe material to prevent entrapment of air bubbles. The water-soaked outer layer of the hydrocolloid-loaded tray and the gauze covering the tray impression cloth are removed to ensure firm bonding to the syringe hydrocolloid. The tray is immediately brought into position, seated with light force per unit area, and held with a very light strength. Besides much pressure may displace the syringed agar sol from the tooth and distort the impression.

Gelation is accelerated by circulating cool h2o (approximately 18 to 21 °C) through the tray for 3 to 5 minutes. During the gelation process, the tray must be held in the rima oris until gelation has proceeded to a point at which the gel forcefulness is sufficient to resist deformation or fracture.

As discussed earlier in the section on elastomeric impression materials, hydrocolloid materials exhibit viscoelastic behavior; therefore information technology is necessary to remove the impression with a snap and non to tease it out. Any twisting or flexure should exist avoided. When properly done, the resulting impression will accurately reproduce the dimensions and details of hard and soft tissues.

Nutrient Science Basics: Healthy Cooking and Baking Demystified

Jacqueline B. Marcus MS, RD, LD, CNS, FADA , in Culinary Nutrition, 2013

Agar (agar agar)

Agar (agar agar) is a gelatinous substance that is extracted from seaweed and candy into flakes, powders and sheets. It is commonly used in Asian cuisines and as a flavorless vegan substitute for gelatin. Agar helps gel, stabilize, texturize and thicken beverages, baked goods, confectioneries, dairy products, dressings, meat products and sauces.

Agar gels at low concentrations; the gel is opaque in color and chewy in texture, making information technology versatile in both cold and hot dishes. A general rule of pollex is to utilize 1 tablespoon of agar flakes or 1 teaspoon of agar powder to thicken 1 cup of liquid.

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Attacking the enemy : Antimicrobial agents and chemotherapy

Richard V. Goering BA MSc PhD , in Mims' Medical Microbiology and Immunology , 2019

Improvidence tests involve seeding the organism on an agar plate and applying filter newspaper disks containing antibiotics

The isolate to be tested is seeded over the entire surface of an agar plate, and filter newspaper disks containing the antibiotics are applied. After overnight incubation the plate is observed for zones of inhibition around each antibody disk ( Fig. 34.22). The amount of antibody in the disk is related to, among other things, the doable serum concentration and therefore differs for unlike antibiotics. In addition, antibiotics differ in their ability to diffuse in agar, so the size of the inhibition zone (and not merely its presence) is an indicator of susceptibility of the isolate. The zone sizes are compared with those for reference organisms (either tested in parallel or established previously and published in reference tables) and the consequence recorded as 'Due south' (susceptible), 'I' (intermediate) or 'R' (resistant). An 'I' result indicates that the isolate is less susceptible than the norm, simply may respond to higher doses of antibiotic or in sites where the antibiotic is concentrated (east.1000. in urine in the bladder for antibiotics excreted by the kidneys).

Choice and Awarding of Culture Media

Tim Sandle , in Biocontamination Control for Pharmaceuticals and Healthcare, 2019

Blood Agar

Blood agar, such equally Columbia blood agar, is a highly nutritious full general-purpose agar. Blood Agar is a general-purpose enriched medium oftentimes used to grow fastidious organisms and to differentiate leaner based on their hemolytic backdrop. This medium is used for some microbiological identification tests.

Of the agars described it is virtually mutual for TSA to be used, either solely or in conjunction with SDA. Nutrient agar is a nutrient medium most effectively used for the tillage of microorganisms supporting growth of a broad range of nonfastidious organisms, and blood agar is nearly appropriate for human-related organisms, in clinical practice.

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FUNGI | Foodborne Fungi

A.D Hocking , in Encyclopedia of Food Microbiology (Second Edition), 2014

Aflatoxins

AFPA cannot be used to screen for aflatoxin product, but coconut cream agar (CCA) can exist used to notice aflatoxin production in A. flavus and A. parasiticus. CCA is made using any brand of commercial canned coconut foam. Dilute l:50 with water, add agar (ane.five%), and autoclave. Inoculated CCA should be incubated at 25–30   °C for v–7   days. Examine colonies, reverse upmost, under a long-wave length ultraviolet (UV) light. Colonies producing aflatoxins fluoresce bluish white or white, especially in the centers. An uninoculated CCA plate can be used as a control, just a plate inoculated with known nontoxigenic and toxigenic strains provides a better comparison.

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Tissue processing

Lena T. Spencer , John D. Bancroft , in Bancroft's Theory and Do of Histological Techniques (Seventh Edition), 2013

Agar

Agar gel lone does not provide sufficient support for sectioning tissues. Its main employ is as a cohesive amanuensis for pocket-size friable pieces of tissue after fixation, a procedure known every bit double embedding. Fragments of tissue are embedded in melted agar, allowed to solidify and trimmed for routine processing. A superior, more refined, method is to filter the fixative containing small, friable tissue fragments through a Millipore filter using suction. Molten agar is and so carefully poured into the filter apparatus, the agar is left to solidify and the resultant agar pellet is removed and routinely processed and embedded in methane series wax.

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Polymers in Biological science and Medicine

E.-H. Song , ... D.Grand. Ratner , in Polymer Scientific discipline: A Comprehensive Reference, 2012

9.08.3.4.1(ii) Applications

Agar is the most ordinarily used growth medium for microorganisms. Due to the ease with which agar can be transported (dry out, dissolved, and gelled), it is ubiquitous in the modern-day laboratory. Solid agar plates can back up microbial growth when supplemented with appropriate nutrients or be used for antibody selection. Agar media is essential for the study of microorganisms and molecular biology and is widely used in the culture and detection of pathogens from contaminated nutrient and water. 173 In addition, due to its porous 3D framework, agar is often used in biomolecular separation and purification. Agar is one of the near common basic media for gel electrophoresis, gel bead chromatography, and size exclusion chromatography. 174–176

In improver to its use equally a solid growth media, agar has been fabricated in different forms (e.g., microspheres and films) to encapsulate molecules for sustained-drug commitment 177 or immobilize proteins for tissue engineering science. 178 Due to the gelation property of agar, it is most often used as a hydrogel. To realize sustained-drug commitment, agar hydrogels have been modified by integrating other biopolymers to class an interpenetrating network. This network structure of agar hydrogels is able to improve the mechanical holding of the drug delivery systems and also extend the drug release profile. 179 In tissue engineering, agar hydrogels with high porosity have shown promising results to promote cell adhesion and proliferation. 180

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Tissue processing

Dee Wolfe , in Bancroft's Theory and Practice of Histological Techniques (Eighth Edition), 2019

Agar

Agar gel alone does not provide sufficient support for sectioning tissues. Its main utilize is as a cohesive agent for small friable pieces of tissue afterwards fixation, a process known as double embedding, when fragments of tissue are embedded in melted agar, allowed to solidify and trimmed for routine processing. Some other method is to filter the fixative containing small, friable tissue fragments through a Millipore filter using suction. Molten agar is then carefully poured into the filter apparatus, the agar is left to solidify and the resultant agar pellet is removed and routinely candy and embedded in methane series wax. An equivalent system is the use of cheese spread (meet Chapter 5).

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ELECTROPHORESIS | Overview

R. Stringer , in Encyclopedia of Belittling Science (2d Edition), 2005

Agar Gel Electrophoresis

Agar is a mixture of two galactose-based polymers, agarose and agarpectin. Agar will solubilize in aqueous buffers above 40°C and sets to class a gel at ∼38°C. The gel has a big pore size and low frictional resistance enabling a rapid motion of ions, which assists in the separation of macromolecules. Agar gels can be used for separating nucleic acids at a lower cost than agarose gels (described next). A disadvantage to agar every bit a medium is that electroendosmosis is severe unless its sulfur content is removed prior to purification. Citrate agar electrophoresis is routinely used clinically to identify hemoglobins, for example, in diagnosis of sickle cell anemia.

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Natural polymers every bit constituents of bionanocomposites

Aqdas Noreen , ... Sitwat Sultana , in Bionanocomposites, 2020

3.2.x Agar

Agar is a water-soluble polysaccharide and forms a gel but is insoluble in cold h2o. Information technology is obtained from agarophyte members of the Rhodophyta. Information technology mostly comprises repeating anaerobioses units alternating between 3-linked β- d-galactopyranosyl (K) and four-linked 3,vi- anhydro-α-l-galactopyranosyl units. Agar is non easily metabolized by microorganisms and forms a articulate, stable, and firm gel and so it is used in microbiological media. In the food region, it is extensively used in glazes, icings, processed cheese, jelly sweets, and marshmallows [97] (Fig. 3.11).

Figure 3.11. Chemical construction of agar [97].

Agar films are clear, transparent, flexible, and strong at low moisture content [98], but their utilization in nutrient packaging has been limited due to their hydrophilicity and depression mechanical and bulwark properties [99]. The employ of NPs as reinforcement is the all-time solution to overcome these limitations. Atef et al. [100] prepared nanocrystalline cellulose from microcrystalline cellulose and incorporated them into agar motion picture to class agar nanocomposite films for food packaging. Rhim et al. [101] isolated CNCs from onion peel and prepared agar/CNC blended films. Smart actuators accept recently been extensively used in wearable devices, microrobots, and artificial muscles. Wang et al. [102] reported a novel polypyrrole/agar nanocomposite smart actuator for a walking device with a quick response time, programmable shape-changing capability, large deformation, and multistimuli response bent.

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