Polymorphic Transformation
Polymorphic Transformation - Related Videos
04:33
Bacterial Transformation - Concepts
0 Views •
2019
Background In early 20th century, pneumonia was accountable for a large portion of infectious disease deaths1. In order to develop an effective vaccine against pneumonia, Frederick Griffith set out to study two different strains of the Streptococcus pneumoniae: a non-virulent strain with a rough appearance (R-strain) and a virulent strain with a smooth appearance (S-strain) due to an outer polysaccharide capsule2. This outer layer of the S-strain bacteria enabled them to withstand the host...
05:21
Bacterial Transformation - Student Protocol
0 Views •
2019
Bacterial Transformation ExpandIMPORTANT: In addition to wearing the appropriate personal protective equipment, be sure to take care to keep your face away from suspension cultures, and to avoid inhaling reagents. Do not touch your face while performing the experiment. Always wash your hands before and after every experiment. When you are ready to safely begin, check to make sure you have a tube or tubes of competent E. coli cells in your ice bucket. Then, transfer 50 µL from one of these tubes...
10:01
The Visual Colorimetric Detection of Multi-nucleotide Polymorphisms on a Pneumatic Droplet Manipulation Platform
0 Views •
Cited by 2 •
2016
This work presents a simple and visual method to detect multi-nucleotide polymorphisms on a pneumatic droplet manipulation platform. With the proposed method, the entire experiment, including droplet manipulation and detection of multi-nucleotide polymorphisms, can be performed near 23 °C without the aid of advanced instruments.
12:19
Bacterial Transformation: Electroporation
0 Views •
2023
The term “transformation” refers cellular ingestion of foreign DNA. In nature, transformation can occur in certain types of bacteria. In molecular biology, however, transformation is artificially induced through the creation of pores in the bacterial cell walls. Bacterial cells that are able to take up DNA from the environment are called competent cells. Electrocompetent cells can be produced in the laboratory and transformation of these cells can be achieve via the application of an...
08:30
Yeast Transformation and Cloning
0 Views •
2023
S. cerevisiae are unicellular eukaryotes that are a commonly-used model organism in biological research. In the course of their work, yeast researchers rely upon the fundamental technique of transformation (the uptake of foreign DNA by the cell) to control gene expression, induce genetic deletions, express recombinant proteins, and label subcellular structures. This video provides an overview of how and why yeast transformation is carried out in the lab. The important features of yeast...
FAQs
Each polymorph has a distinct crystal arrangement and therefore a distinct stability under specified conditions. Changing temperature or pressure can alter which arrangement is energetically favored, prompting the solid to reorganize or transform. Tracking these condition-dependent changes helps chemists identify the form most likely to persist during storage, processing, or other experiments.
Solvents and humidity can change the surroundings at crystal surfaces and affect which solid form is favored. Under suitable conditions, a polymorph may dissolve and later recrystallize as another form, while moisture or solvent exposure may also support rearrangement within the solid. These variables must therefore be considered when assessing crystal stability.
A solution-mediated pathway includes dissolution followed by nucleation and recrystallization, allowing a different polymorph to form from the surrounding solution. In a direct solid-state transformation, the crystal rearranges without the overview’s dissolution and recrystallization sequence. Distinguishing these pathways clarifies how temperature, pressure, solvent, or humidity produced the observed structural change.
Rearranging the crystal structure can change melting point, solubility, density, mechanical behavior, and reactivity even though the compound’s molecular composition is unchanged. Consequently, two forms of the same compound may behave differently during handling, formulation, purification, or use. Measuring these properties reveals whether a transformation improves or compromises the intended performance.
Temperature, pressure, solvent environment, and humidity are the principal conditions to control because each can influence crystal stability and the route of transformation. Researchers can vary these factors systematically, then determine which crystal form results and how its properties differ. Such comparisons help establish conditions that favor a desired form or limit unwanted change.
Different polymorphs can have different solubilities, melting points, densities, and mechanical properties, all of which can affect how a pharmaceutical material performs. Controlling transformation helps formulators select and maintain a crystal form with suitable behavior. Stability studies are therefore important for understanding whether processing or storage conditions could shift the material to another form.
In purification, selecting conditions that favor one polymorph can help separate or isolate a desired crystalline form. Crystal engineering uses the same relationship between conditions and structure to pursue materials with predictable properties. By controlling transformation rather than treating it as an incidental change, chemists can connect crystal structure with performance and stability.
A transformation study can identify which crystal form is favored under particular temperature, pressure, solvent, or humidity conditions and reveal how that form differs in physical or chemical behavior. These findings support comparisons of stability, solubility, reactivity, and mechanical performance. They also provide a basis for designing chemical materials and formulations with more predictable properties.