A form of nanoscale steganography exists described as DNA origami cryptography which is a technique of secure information encryption through scaffold, staple, and varying docking strand self- assembling mixtures. The all-DNA steganography based origami was imaged through high-speed DNA-PAINT super-resolution imaging which uses periodic docking sequences to eliminate the need for protein binding. The purpose of this research was to improve upon the DNA origami cryptography protocol by encrypting information in 2D Rothemund Rectangular DNA Origami (RRO) and 3D cuboctahedron DNA origami as a platform of self-assembling DNA nanostructures to increase the routing possibilities of the scaffold. The initial focus of the work was increasing the incorporation efficiency of all individual docking spots for full 20nm grid RRO pattern readout. Due to this procedural optimization was pursued by altering annealing cycle length, centrifugal spin rates for purification, and lengthening docking strands vs. imager poly T linkers. A 14nm grid was explored as an intermediate prior to the 10nm grid for comparison of optimized experimental procedure for a higher density encryption pattern option. Imager concentration was discovered to be a vital determining factor in effectively resolving the 10nm grids due to high concentrations of imager strands inducing simultaneous blinking of adjacent docking strands to be more likely causing the 10nm grids to not be resolved. A 2 redundancy and 3 redundancy encryption scheme was developed for the 10nm grid RRO to be encrypted with. Further experimentation was completed to resolve full 10nm DNA-origami grids and encrypt with the message ”ASU”. The message was successfully encrypted and resolved through the high density 10nm grid with 2 and 3 redundancy patterns. A cuboctahedron 3D origami was explored with DNA-PAINT techniques as well resulting in successful resolution of the z-axis through variation of biotin linker length and calibration file. Positive results for short message ”0407” encryption of the cuboctahedron were achieved. Data encryption in DNA origami is further being explored and could be an optimal solution for higher density data storage with greater longevity of media.
Neurospora crassa is a red mold that scientists use to study genetics. N. crassa commonly grows on bread as shown in the top left corner of this figure. To culture the mold in lab, researchers grow it in glassware such as test tubes, Erlenmeyer flasks, and petri dishes, as shown in the top right corner of the figure. In the glassware, researchers place a gel, called a medium, of agar, sucrose, salts, and vitamins. The mold grows on the medium, and cotton stoppers prevent anything from contaminating the mold. Under a microscope, researchers can see the structure of the mold's ascospores, which are haploid and oval-shaped structures and function in the mold's life cycle as seeds function in a plant's life cycle.
This diagram shows the life cycle of Neurospora crassa, a mold that grows on bread. N. crassa can reproduce through an asexual cycle or a sexual cycle. The asexual cycle (colored as a purple circle), begins in this figure with (1a) vegetative mycelium, which are strands of mature fungus. Some of the strands form bulbs (2a) in a process called conidiation. From those bulbs develop the conidia, which are spores. Next, (3a) a single conidium separates from its strand and elongates until it forms mycelium. The sexual cycle (colored as an orange circle) also starts with the (1b) vegetative mycelium. The strands develop into a structure called the proto-perithecium, and reproduction involves the proto-perithecium interacting with the conidia from a different mycelium. Reproduction also involves two mating types, called type A and type a. In reproduction, type A pairs with type a, and a conidium can be of either type, as can a proto-perithecium. A proto-perithecium fertilized by a conidium of the opposite mating type (2b) will develop into a perithecium. Inside the perithecium, croziers develop and mature into asci. (3b) In a maturing ascus, there are two nuclei (one represented as a white circle and one as a black circle), one of which comes from the conidium and the other from the proto-perithecium. Each nuclei has only one set of chromosomes (haploid). The two haploid nuclei fuse into a diploid nucleus (represented as a half black half white circle). The nucleus then divides, separating into two nuclei each with one set of chromosomes. Those nuclei duplicate themselves (represented as two white circles and two black circles), and then all the nuclei duplicate themselves again (represented as four white circles and four black circles). This process yields eight haploid ascospores within a mature ascus. Ascospores are spores, and function for the mold as do seeds for plants. The mature perithecium releases its ascospores (4b), which germinate and grow into mycelium. In the 1930s and 1940s, George Beadle and Ed Tatum collected the spores of irradiated N. crassa to study how genes produced enzymes.
Magnetic Resonance Microscopy (MRM) is an imaging method that allows the visualization of internal body structures. Using powerful magnets to send energy into cells, MRM picks up signals from inside a specimen and translates them into detailed computer images. MRM is a useful tool for scientists because of its ability to generate digital slices of scanned specimens that can be constructed into virtual 3D images without destroying the specimens. MRM has become an increasingly prevalent imaging technique in embryological studies. Through MRM, the first 3D human embryo images were created as part of the "Multi-Dimensional Human Embryo" project, a public database of three-dimensional embryo images.
The Golgi staining technique, also called the black reaction after the stain's color, was developed in the 1870s and 1880s in Italy to make brain cells (neurons) visible under the microscope. Camillo Golgi developed the technique while working with nervous tissue, which required Golgi to examine cell structure under the microscope. Golgi improved upon existing methods of staining, enabling scientists to view entire neurons for the first time and changing the way people discussed the development and composition of the brain's cells. Into the twenty-fist century, Golgi's staining method continued to inform research on the nervous system, particularly regarding embryonic development.
Elizabeth Dexter Hay studied the cellular processes that affect development of embryos in the US during the mid-twentieth and early twenty-first centuries. In 1974, Hay showed that the extracellular matrix, a collection of structural molecules that surround cells, influences cell behavior. Cell growth, cell migration, and gene expression are influenced by the interaction between cells and their extracellular matrix. Hay also discovered a phenomenon later called epithelial-mesenchymal transition, a process that occurs during normal embryo and adult development in which epithelial cells, cells that line external and internal surfaces of the body, transform into mesenchymal stem cells, connective tissue cells that are capable of turning into other cell types. Hay's work helped researchers explain normal developmental processes and enabled research into abnormal processes that can cause developmental defects and diseases.
Marcello Malpighi studied chick embryos with microscopes in Italy during the seventeenth century. Trained as a medical doctor, he was among the first scientists to use the microscope to examine embryos at very early stages. Malpighi described early structures in chick embryos, and later scientists used his descriptions to help develop the theory of preformationism.
Label-free Biomolecule Characterization and Functional Study by Surface Sensitive Optical Microscopy
Antoni van Leeuwenhoek was born in Delft, the Netherlands, on 24 October 1632 to Margriet Jacobsdochter van den Berch and Philips Thooniszoon, both of whom were middle-class artisans. He attended grammar school in Warmond, and then temporarily moved to Benthuizen to live with relatives. Eventually Leeuwenhoek left for Amsterdam to work as a cloth merchant's apprentice. Returning to Delft, he married Barbara de Mey on 29 July 1654, and worked as a shopkeeper. The marriage resulted in five children, only one of whom, Maria, outlived Leeuwenhoek.