Cytoskeleton: Cell Motility and Subcellular Movement

In Lab 3, participants will engage in a series of comprehensive activities dedicated to understanding the cytoskeleton, cell motility, and the intricate observation of subcellular movements across a variety of microorganisms. These activities will include preparing gadget swabs for microbiota surveys, which involves carefully collecting samples from surfaces to study the microbial diversity that exists in our environment. Participants will examine motility and feeding behaviors in specific organisms, including Paramecium, Euglena, and Amoeba, through hands-on microscopy, allowing for real-time observation of their unique locomotion and feeding mechanisms. Additionally, students will observe a mixed culture isolated from spinach, providing insight into how different microorganisms coexist and interact in natural environments. Demonstrations utilizing advanced fluorescence microscopy will significantly enhance participants’ understanding of cellular structures, enabling them to visualize and study specific cellular components at a molecular level, which is crucial for connecting cellular structure with function.

Gadget Microbiota Survey Objectives

A primary goal of this lab is to implement mobile devices as innovative tools for microbiological exploration. Participants will take phone imprints on nutrient-rich agar plates designed to cultivate bacterial samples, which will be meticulously analyzed in subsequent labs to determine microbial growth and diversity. The significance of this experiment lies in understanding the growth patterns of culturable microorganisms, particularly in relation to public health, as well as addressing the implications of antibiotic resistance that has emerged in various microbial populations. This highlights the critical need for sterile techniques in laboratory settings to prevent contamination and ensure accurate results. Participants must observe rigorous safety precautions, including the mandatory use of personal protective equipment (PPE) such as lab coats, gloves, and safety glasses to mitigate risks associated with microbial handling.

Importance of Aseptic Techniques

To prevent unwanted contamination, it is essential to strictly adhere to aseptic (sterile) techniques throughout the laboratory procedures. A pure culture is paramount for obtaining accurate observations, as microorganisms are omnipresent in the environment. In the laboratory, rolling out a pure culture involves isolating and culturing genetically identical cells that allow for the observation of their behavior free from the interference of external microbial populations. Systematic contamination can be reduced by employing proper aseptic methodologies such as flame sterilization of tools, proper handling of cultures, and minimizing exposure of sterile media to the environment.

Media and Microbial Growth

Microbial growth is facilitated by specific culture media, which are formulated to nourish cells and promote their multiplication effectively. Trypticase soy (TCS) agar is a rich medium that encompasses proteins and nutrients vital for sustaining microbial growth. The visible growth of colonies on these media represents large aggregates of genetically identical cells, enabling participants to observe and analyze microbial diversity and density harvested from environmental sources such as mobile phones. These observations can provide valuable insights into the prevalence of various microorganisms and their potential impact on hygiene practices.

Comparison of Different Cultures

This lab will serve as an engaging comparative exercise, aiming to contrast both the number and types of bacterial colonies collected from distinct phone samples within the class. This experiential learning objective is designed to familiarize students with the vast abundance of microorganisms present in everyday environments and elucidate their implications for sterile laboratory practices, as well as public health concerns.

Cell Observations in Different Organisms

Through the use of microscopy, students will observe and critically analyze various cell types and their unique movement patterns:

Paramecium Observations

Participants will closely examine Paramecium, a unicellular organism that employs cilia for both locomotion and feeding purposes. The cilia function to propel food particles toward the oral groove, facilitating the formation of food vacuoles via phagocytosis—a key process in their nutritional uptake. Additionally, contractile vacuoles play a pivotal role in maintaining osmotic balance within Paramecium, demonstrating their importance in cellular homeostasis. Specific behaviors, including swimming patterns and digestion processes, will be meticulously analyzed under varying magnifications using light microscopes to appreciate the scale and complexity of these organisms.

Euglena Behavior

Euglena will also be scrutinized for its distinctive swimming motion, which is propelled by a whip-like flagellum, as well as its ability to photosynthesize due to the presence of chloroplasts. Participants will focus on observing the dynamics of locomotion and other cellular activities, noting distinct differences in movement and behavior compared to Paramecium, thus broadening their understanding of different modes of life in microorganisms.

Amoeba Movement

Amoebas will be viewed specifically to illustrate their characteristic amoeboid movement, which is mediated by the extension and retraction of pseudopodia. This study will highlight how microfilaments coordinate to create both fluidity and rigidity within the cytoplasm, facilitating the cell’s movement as it adapts to its environmental conditions.

Microscope Characteristics and Enhancements

Various microscopy approaches will be utilized to refine and enhance the observations:

1. Contrast: Participants will learn to enhance contrast in their imaging techniques using staining methods or by employing oil immersion with light microscopes, significantly improving the clarity necessary for visualizing transparent specimens.

2. Resolution: Understanding how to calculate resolution value is essential for accurately distinguishing between closely positioned cellular structures. The formula for resolution not only involves the numerical aperture and wavelength but also underscores the intricate relationship between optics and cellular observations in microscopy.

3. Fluorescence Microscopy: Demonstrations will include observing unique specimens such as transgenic C. elegans, which have been engineered to express green fluorescent protein, facilitating enhanced visualization during the examination of nucleic and cellular structures. This technique exemplifies the advancements in microscopy that enable modern scientists to connect structure with function at a cellular level.

Conclusion and Cleanup Process

At the conclusion of the lab, participants will be expected to meticulously clean their workstations, disposing of materials responsibly, including glass waste and biohazardous materials. Proper procedures must be adhered to throughout the cleanup process, ensuring PPE is worn at all times during lab activities to maintain both individual and community safety, thereby reinforcing the importance of safety in microbiological research.

Results Documentation and Future Labs

Students will be required to document their observations and reflections comprehensively, linking expected outcomes with actual results. This process will encourage participants to draw connections between the lab activities and theoretical concepts discussed in lectures. Future labs will build upon these foundational observations, linking microbiological principles to broader biological contexts while reinforcing the necessity for stringent microbial handling protocols to ensure safety and accuracy in scientific inquiry.

In Lab 3, students will participate in activities to learn about the cytoskeleton, cell movement, and how cells behave in different microorganisms. They will collect samples using gadget swabs from various surfaces to study the microbes in our environment.

Gadget Microbiota Survey Goals

One of the main goals of this lab is to use mobile devices to help explore microbiology. Students will take samples from their phones and place them on special nutrient agar plates that encourage bacterial growth. They will analyze these samples later to see how many and what types of bacteria are present. Understanding how bacteria grow is important for public health, especially concerning antibiotic resistance, which is when bacteria become resistant to medications. Students must follow safety rules, like wearing gloves and lab coats, when handling these samples.

Importance of Aseptic Techniques

To avoid contamination, students need to follow clean methods during lab work. Having a pure culture means they can observe microorganisms without interference from other bacteria. This requires careful handling, sterilizing tools, and limiting exposure to the environment.

Media and Microbial Growth

Bacteria grow in certain cultures that provide food and nutrients. Trypticase soy (TCS) agar is one that is rich in proteins. When bacteria grow on these media, they form colonies that show how many microorganisms were present originally. This can help students understand hygiene and the importance of cleanliness.

Comparing Different Cultures

Students will compare bacterial samples collected from different phones in class. This will help them learn about microorganisms that are all around us and their relationship to safety in the lab and health concerns.

Observing Different Organisms

Students will use microscopes to look at different types of cells and their movement:

Paramecium Observations

They will examine Paramecium, a single-celled organism that uses tiny hair-like structures called cilia for movement and feeding. The cilia help push food into the cell, and contractile vacuoles help control water levels, which is essential for cell stability.

Euglena Behavior

Students will also study Euglena, which moves using a whip-like tail (flagellum) and can make its own food using sunlight. They will observe how it moves differently from Paramecium.

Amoeba Movement

Amoebas will be observed to show how they change shape to move, which is done by extending their body parts called pseudopodia. This movement helps them adapt to their surroundings.

Microscopy Techniques

Students will try different microscope techniques to get clearer images:

1. Contrast: Enhancing visibility using stains or oil will make it easier to see transparent specimens.

2. Resolution: Learning how to calculate resolution helps in distinguishing close cellular structures.

3. Fluorescence Microscopy: They will see specimens like genetically modified C. elegans that glow under the microscope, making it easier to study their structures.

Cleanup Process

After the lab, students must clean their work areas properly, disposing of materials correctly, including biohazard waste, while still wearing PPE for safety.

Documentation and Future Labs

Students will keep track of their observations and what they learned, helping them connect lab findings with what they discuss in class. Future labs will build on these experiences, linking microbiological concepts to broader biological topics while emphasizing safe microbial practices.