1: Visualizing Cells through Microscopy
- Page ID
- 173527
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Before we can even begin to discuss cells, it’s important to understand that cells are very tiny! Most cells are too small to see with the naked eye. Thus, the beginning of our book must start with a conversation about microscopes and how they work. An understanding of the tools we use to study cells, both their abilities and their limitations, is essential to making sense of the material you’re going to be exploring throughout this book.
- 1.1: Prelude to Visualizing Cells through Microscopy
- This page discusses the evolution of microscopes over the past 50 years, focusing on four main types: brightfield light microscopy, fluorescence light microscopy, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). It highlights advancements in using electrons for superior magnification and resolution compared to early visible light methods.
- 1.2: Magnification and Resolution
- This page explores magnification and resolution in microscopy, defining magnification as the enlargement of objects and resolution as the ability to distinguish nearby structures. It highlights the differences in resolution limits between light (up to 175 nm) and electron microscopy (0.1 nm), allowing for visualization of finer details. The text emphasizes the need to align resolution with magnification for effective microscopy.
- 1.3: Light Microscopy
- This page provides an overview of light microscopy, detailing its types (e.g., brightfield, fluorescence) and operational techniques, including transmitted and emitted light methods. It discusses applications like real-time observation of live cells, the preparation of samples for fluorescence microscopy, and the use of fluorescent markers such as GFP for visualizing cellular components and tracking protein interactions.
- 1.4: Electron Microscopy
- This page provides an overview of electron microscopy, emphasizing transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Both methods utilize electron beams in a vacuum for high-resolution imaging, surpassing light microscopy. However, sample preparation is often complex. TEM reveals detailed internal structures of thin samples, whereas SEM captures surface details. Limitations include specimen thickness for TEM and limited depth visibility in SEM.
- 1.5: Interpreting Micrographs
- This page outlines essential learning goals for interpreting microscopy results, focusing on identifying microscopy types based on scale, magnification, and resolution. It offers guidance for analyzing micrographs with questions regarding magnification and other aspects. The differences between light and electron microscopy are explained, including tips on distinguishing various methods.
- 1.6: End-of-Chapter Material
- This page highlights the importance of microscopes in cell biology, detailing various types such as brightfield, fluorescent, transmission electron, and scanning electron microscopy. Each type has distinct magnification, resolution, and sample preparation needs, which are essential for accurate imaging. Review questions are included to enhance understanding and engagement with microscopy concepts, supporting students in acquiring necessary skills for studying cell biology.
Thumbnail: This is a scanning electron microscope image from normal circulating human blood. One can see red blood cells, several white blood cells including lymphocytes, a monocyte, a neutrophil, and many small disc-shaped platelets. (Public Domain; Bruce Wetzel (photographer) and Harry Schaefer (photographer) via Wikipedia)