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American Journal of Clinical Pathology Apr 1979Concave deformaties of the bottom of Petri dishes are a potential source of error for disk agar diffusion antibiotic assay and susceptibility procedures. This is due to...
Concave deformaties of the bottom of Petri dishes are a potential source of error for disk agar diffusion antibiotic assay and susceptibility procedures. This is due to differences in agar depth between the central and peripheral areas of the Petri dishes. We have observed significant concave deformities in both empty and commercially filled 150-mm plastic Petri dishes. For this reason we recommend that inspections for Petri dish deformity be incorporated into microbiology laboratory quality control programs.
Topics: Anti-Bacterial Agents; Gentamicins; Microbial Sensitivity Tests; Microbiological Techniques; Pseudomonas aeruginosa; Quality Control
PubMed: 108994
DOI: 10.1093/ajcp/71.4.433 -
Micromachines Sep 2020In this paper, we report on a novel biocompatible micromechanical bioreactor (actuator and sensor) designed for the in situ manipulation and characterization of live...
In this paper, we report on a novel biocompatible micromechanical bioreactor (actuator and sensor) designed for the in situ manipulation and characterization of live microtissues. The purpose of this study was to develop and validate an application-targeted sterile bioreactor that is accessible, inexpensive, adjustable, and easily fabricated. Our method relies on a simple polydimethylsiloxane (PDMS) molding technique for fabrication and is compatible with commonly-used laboratory equipment and materials. Our unique design includes a flexible thin membrane that allows for the transfer of an external actuation into the PDMS beam-based actuator and sensor placed inside a conventional 35 mm cell culture Petri dish. Through computational analysis followed by experimental testing, we demonstrated its functionality, accuracy, sensitivity, and tunable operating range. Through time-course testing, the actuator delivered strains of over 20% to biodegradable electrospun poly (D, L-lactide-co-glycolide) (PLGA) 85:15 non-aligned nanofibers (~91 µm thick). At the same time, the sensor was able to characterize time-course changes in Young's modulus (down to 10-150 kPa), induced by an application of isopropyl alcohol (IPA). Furthermore, the actuator delivered strains of up to 4% to PDMS monolayers (~30 µm thick), simultaneously characterizing their elastic modulus up to ~2.2 MPa. The platform repeatedly applied dynamic (0.23 Hz) tensile stimuli to live Human Dermal Fibroblast (HDF) cells for 12 hours (h) and recorded the cellular reorientation towards two angle regimes, with averages of -58.85° and +56.02°. The device biocompatibility with live cells was demonstrated for one week, with no signs of cytotoxicity. We can conclude that our PDMS bioreactor is advantageous for low-cost tissue/cell culture micromanipulation studies involving mechanical actuation and characterization. Our device eliminates the need for an expensive experimental setup for cell micromanipulation, increasing the ease of live-cell manipulation studies by providing an affordable way of conducting high-throughput experiments without the need to open the Petri dish, reducing manual handling, cross-contamination, supplies, and costs. The device design, material, and methods allow the user to define the operational range based on their targeted samples/application.
PubMed: 32993158
DOI: 10.3390/mi11100892 -
Journal of Biomedical Materials... Oct 2021The cell microenvironment such as substrate topology plays an important role in biological processes. In this study, microgrooves were successfully produced on surfaces...
The cell microenvironment such as substrate topology plays an important role in biological processes. In this study, microgrooves were successfully produced on surfaces of both thermoplastic and thermoset polymers using cost-effective techniques for mass production. The micropatterning of thermoplastic polystyrene (PS) petri dish was accomplished efficiently using an in-house developed low-cost hot embossing system. The high replication fidelity of the microgroove with depth and width of 2 μm and spacing of 2 μm was achieved by using silicone rubber as a soft counter mold. This patterned petri dish subsequently served as the cast to replicate the micropattern onto thermoset polydimethylsiloxane (PDMS). It was found that the micropattern increased the hydrophobicity of both PS and PDMS surfaces. The effect of the substrate micropattern on cellular behaviors was preliminarily investigated with untreated and treated PS petri dish as well as PDMS. The results show that the micropattern significantly improved cell adhesion and proliferation for cells cultured on untreated PS petri dish and PDMS substrates. Moreover, the micropattern induced obvious cell alignment along the microgrooves for culturing on all substrates which were studied.
Topics: Cell Adhesion; Cell Culture Techniques; Cell Proliferation; Coated Materials, Biocompatible; Dimethylpolysiloxanes; Hydrophobic and Hydrophilic Interactions; Mesenchymal Stem Cells; Polystyrenes; Surface Properties
PubMed: 33590658
DOI: 10.1002/jbm.b.34811 -
ACS Applied Materials & Interfaces Jun 2014Nano-petri-dish array assisted glancing angle Ag-sputtering was reported to synthesize Ag-nanoparticle (Ag-NP) assembled bi-nanoring arrays as surface-enhanced Raman...
Nano-petri-dish array assisted glancing angle Ag-sputtering was reported to synthesize Ag-nanoparticle (Ag-NP) assembled bi-nanoring arrays as surface-enhanced Raman scattering (SERS) substrates. By manipulating the sputtering-Ag duration, the gaps between the Ag-NPs in the bi-nanorings are tunable to acquire optimal electromagnetic field enhancement, and the ordered bi-nanoring arrays ensure excellent reproducibility for Raman measurement. Such as-fabricated Ag-NPs assembled nanoring arrays exhibit excellent SERS performance, not only 1 × 10(-12) M rhodamine 6G has been identified, but also polychlorinated biphenyls with a low concentration down to 1 × 10(-9) M has been recognized, showing great potential in the detection of trace organic pollutants in the environment.
PubMed: 24869912
DOI: 10.1021/am502793d -
Journal of Law and the Biosciences Aug 2018Advancing technologies in genetic testing of preimplantation embryos enable IVF patients to access detailed information about their future child's health status,...
Advancing technologies in genetic testing of preimplantation embryos enable IVF patients to access detailed information about their future child's health status, facilitating and complicating their reproductive decision-making. Testing for embryonic genetic anomalies linked to future health has grown increasingly sophisticated. A patient's decision to seek transfer of a health-affected embryo may or may not be compatible with her physician's professional conscience, potentially resulting in a clash at the petri dish. This article sets out arguments in support of physician decisions to assist or decline to assist in the transfer of anomalous embryos upon patient request. Arguments in support of transfer include the preeminence of a patient's reproductive liberty, the value of equal protection as applied to pre- and post-implantation embryos, the allocation of dispositional authority over embryos, and the frailties of predicting a child's future health experience. Arguments that bolster a provider's decision to decline requests for transfer include the role of physician autonomy in the doctor-patient relationship, the theories of reproductive non-maleficence and procreative beneficence, and legitimate concerns over future legal liability. Regardless of a clinic's ultimate position, this article advocates that providers create or adopt detailed policies setting forth their preferences and practices regarding anomalous embryo transfer.
PubMed: 30191065
DOI: 10.1093/jlb/lsy015 -
Biotechnic & Histochemistry : Official... Nov 1996This work describes a new apparatus for growing fungi and other microorganisms on liquid nutrient media in a Petri dish. The apparatus is composed of a net supporting a...
This work describes a new apparatus for growing fungi and other microorganisms on liquid nutrient media in a Petri dish. The apparatus is composed of a net supporting a cellophane membrane stretched between an outer and an inner ring that is placed inside a Petri dish. This modification of the standard Petri dish offers many advantages for studying growth, metabolism, differentiation, and other aspects of fungi in liquid cultures with minimal waste of expensive chemicals. Monitoring of excreted or absorbed substances by the fungi, the aseptic transfer of undisturbed fungal colonies from dish to dish, and harvesting are made easier, using this apparatus.
Topics: Ascomycota; Culture Media
PubMed: 8957556
DOI: 10.3109/10520299609117178 -
Pathology Nov 1999
Review
Topics: Bacterial Infections; Bacteriological Techniques; DNA, Bacterial; Gene Amplification; Genome, Bacterial; Humans; Internet; Polymerase Chain Reaction
PubMed: 10643023
DOI: 10.1080/003130299104909 -
Biotechnology Progress 2011It is well documented that physiological and morphological properties of anchored cells are influenced by fluid shear stress. Common orbital shakers provide a means of...
It is well documented that physiological and morphological properties of anchored cells are influenced by fluid shear stress. Common orbital shakers provide a means of simultaneously applying shear stress to cells for tens to hundreds of cases by loading the shaker with multiple dishes. However, the complex flow in orbiting dishes is amenable to analytical solution for resolving shear created by the fluid motion only for simplified conditions. The only existing quantification of shear in this flow is an equation that estimates a constant scalar value of shear for the entire surface of the dish. In practice, wall shear stress (WSS) will be oscillatory rather than steady due to the travelling waveform and will vary across the surface of the dish at any instant in time. This article presents a computational model that provides complete spatial and temporal resolution of WSS over the bottom surface of a dish throughout the orbital cycle. The model is reasonably well validated by the analytical solution, with resultant WSS magnitudes that are within 0.99 ± 0.42 dyne/cm(2) . The model results were compared to tangential WSS magnitudes obtained using one-dimensional optical velocimetry at discreet locations on the bottom of an orbiting dish. The experimental minimum and maximum WSS at 1 mm from the center of the dish were 6 and 7 dyne/cm(2) , respectively, whereas WSS generated from the computational model ranged from 0.5 to 8.5 dyne/cm(2) . The experimental minimum and maximum WSS at 12 mm from the center of the dish were 6 and 16 dyne/cm(2) , respectively, whereas WSS generated from the computational model ranged from 0.5 to 14 dyne/cm(2) . Discrepancies between the experimental and computational data may be attributed to a sparse sampling rate for the experimental probe, a sharp gradient at the sample area which could cause the unidirectional probe to be inaccurate if its location were not precise, and too few particles to track and a scattering of the signal by the free surface when the liquid is shallow.
Topics: Animals; Cell Adhesion; Cell Culture Techniques; Humans; Models, Theoretical; Rheology; Shear Strength; Stress, Mechanical
PubMed: 21302366
DOI: 10.1002/btpr.507 -
Mathematical Biosciences and... Apr 2013Bacterial competition is an important component in many practical applications such as plant roots colonization and medicine (especially in dental plaque). Bacterial...
Bacterial competition is an important component in many practical applications such as plant roots colonization and medicine (especially in dental plaque). Bacterial motility has two types of mechanisms -- directed movement (chemotaxis) and undirected movement. We study undirected bacterial movement mathematically and numerically which is rarely considered in literature. To study bacterial competition in a petri dish, we modify and extend the model used in Wei et al. (2011) to obtain a group of more general and realistic PDE models. We explicitly consider the nutrients and incorporate two bacterial strains characterized by motility. We use different nutrient media such as agar and liquid in the theoretical framework to discuss the results of competition. The consistency of our numerical simulations and experimental data suggest the importance of modeling undirected motility in bacteria. In agar the motile strain has a higher total density than the immotile strain, while in liquid both strains have similar total densities. Furthermore, we nd that in agar as bacterial motility increases, the extinction time of the motile bacteria decreases without competition but increases in competition. In addition, we show the existence of traveling-wave solutions mathematically and numerically.
Topics: Bacterial Physiological Phenomena; Cell Communication; Cell Culture Techniques; Computer Simulation; Microbial Interactions; Models, Biological
PubMed: 23589930
DOI: 10.3934/mbe.2013.10.399 -
Laboratornoe Delo 1978
Topics: Microbiology
PubMed: 76000
DOI: No ID Found