Exploring with microscopes – introduction
We live in a beautiful world – and that beauty and complexity extends far beyond what humans can see unaided. From plant and animal anatomy to cells and proteins and even down to the level of atoms, there are worlds within worlds of detail to be explored on the microscopic scale.
Liz Girvan’s “world-famous micrograph”
This SEM image of tin spheres of various sizes (used to calibrate the microscope) was taken by Liz Girvan. It won an image competition in Otago and has attracted worldwide interest.
Microscopes are the tools that allow us to look more closely at objects, seeing beyond what is visible with the naked eye. Without them, we would have no idea about the existence of cells or how plants breathe or how rocks change over time. Our understanding of the world around us would be severely limited – and this is why many scientists see microscopes as the most important scientific instrument there is.
Our microscope resources invite students to share in the sense of wonder that scientists have felt for centuries looking through the microscope. We look at the diversity of objects on the microscopic scale and introduce several New Zealand scientists who use microscopes to explore the things that interest them. At the same time, we show how microscopes themselves have evolved to look more and more closely at the world around us.
Which microscope?
Explore the features of different microscopes and learn how scientists choose which ones to use in their research.
Microscopes: technology driving science
Using the earliest microscopes, scientists glimpsed a world of unimaginable complexity – and they wanted to know more. To satisfy this urge, microscope technology became more sophisticated over time, letting us look more and more closely at objects. We’ve been able to ask more specific questions about the object we’re viewing: What does its surface or internal structure look like? What is it made up of? How does it change over time? For each of these questions, specialised microscopes have now been developed that can provide the answers.
Doing microscopy – it’s a dream world. You’re always going to see something beautiful.
Dr Bronwyn Lowe, Clothing and Textile Sciences, within the Department of Applied Sciences, University of Otago
Our microscope resources emphasise the link between microscope technology and the science that microscopes have helped uncover. The activity Which microscope is best? is a good starting point for learning how specialised microscopes can help answer different scientific questions.
New Zealand through the microscope
Two of the research stories we feature have a uniquely Kiwi perspective.
At the University of Otago, Dr Bronwyn Lowe and Māori weavers have been working closely together to explore several properties of harakeke (New Zealand flax). In the article Harakeke under the microscope, learn about the differences between harakeke varieties on the microscopic scale and explore how mātauranga Māori (traditional Māori knowledge) can shed light on scientific research.
Exploring harakeke on the SEM
Dr Bronwyn Lowe (University of Otago) describes her use of scanning electron microscopy (SEM) to explore harakeke leaves. Bronwyn found that different harakeke varieties have differently patterned waxes on the leaf surface. She also explored the distribution of fibre (muka) in the leaves of different varieties.
Point of interest: The fibre that Bronwyn describes is used by Māori weavers to make clothing, mats and other items. Traditionally, weavers strip the fibre from the harakeke leaf using a shell.
New Zealanders are only too aware of how devastating a major earthquake can be. Professor Dave Prior and his group are looking for clues to how and why earthquakes happen. In the article Squishy rocks and earthquakes and the interactive From mountains to microscopes, follow Dave and the team as they collect rock samples from deep in the Alpine Fault (Westland) and see how microscopy of rocks can shed light on the history of movement in the fault.
A closer look at cells
Two further research stories focus on cells in the body.
Dr Rebecca Campbell is studying a small group of brain cells (GnRH neurons) that control fertility. Learn about her remarkable discoveries about how these cells interconnect – all done using microscopes of course!
Making neurons glow
Dr Rebecca Campbell (University of Otago) discusses the importance of fluorescent molecules in confocal laser scanning fluorescence microscopy (‘confocal microscopy’) of cells. She explains how green fluorescent protein (GFP) from jellyfish can be used to make specific neurons glow green.
Point of interest: Look out for the fluorescent jellyfish in this clip!
Jargon alert: Confocal microscopy is a specialised form of optical microscopy that makes it possible to take pictures of many thin slices in a sample without actually slicing the sample up. The individual slices can then be built up into a three-dimensional model.
Jargon alert: Green fluorescent protein (GFP) is the most widely used fluorescent protein in microscopy. When viewed using a confocal microscope, cells containing GFP glow bright green in the parts of the cell where GFP is found. Scientists use GFP and similar fluorescent proteins in many different ways – to label specific types of cell (as Rebecca does), to label individual structures within cells and to look at changes in living cells over time.
Associate Professor Tony Poole shares his story about the primary cilium, a structure of the surface of cells that seems to monitor what’s going on in the cell surroundings. This elusive structure was first tracked down using microscopes, and many aspects of how it works remain mysterious. In the article A closer look at the cell’s antenna, see how Tony is using microscopes to build a 3D computer model of the primary cilium.
Science ideas in exploring with microscopes
Our articles explain some of the big science ideas associated with microscopy:
Take up the challenge
The student activities provide plenty of hands-on experiences. Modelling animal cells in 3D imitates what can be seen under high-resolution microscopes. Using lolly slices to build 3D images and Using shadows to build 3D images model how scientists interpret microscopic data. Ferns under the microscope demonstrates how increasing the power of magnification leads to much greater detail. For younger students use the Making a simple microscope activity – it uses accessible technology to increase students’ ability to observe closely.
The activity Which microscope is best? explores the uses, advantages and limitations of eight types of microscopes.
Question bank
The Exploring with microscopes – question bank provides a list of questions about microscopy and places where their answers can be found. The questions support an inquiry approach.
Key terms
For explanations of key concepts, see Exploring with microscopes – key terms.
Timeline
Use this timeline to discover some of the key advances in microscopy.
