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May/13

20

Immersion Oil Explained

We are often asked about immersion oil so here is a basic primer. Immersion oil is used with high power objectives, typically 90x or 100x.

Light microscopes have an upper limit to their resolving power of marginally over 1,000x. At this level of magnification, the microscope needs to direct every available amount of light in order to achieve a clear image. Since light is refracted and scattered in the air between the objective lens and the slide cover, immersion oil is used to capture much of that ‘lost light’.

In summary, light refracts through air and glass at different angles. The refractive index of air is 1.0 and that of glass, 1.5 so there is considerable refraction between the two. The immersion oil helps to reduce the refraction since it has a refractive index equal to glass. As a result, it forms a continuum between the objective lens and the slide, thereby successfully ensuring that more light is directed towards the specimen and ultimately, a clearer image.

Oil immersion objective lenses are typically engraved with the word “oil”, “immersion” or “HI” (homogenous immersion). They are manufactured with sealants to prevent damage from the oil.
Immersion oils are commonly available in two viscosities-low viscosity (Type A), and high viscosity (Type B). They are often labeled with a refractive index of 1.515. The low viscosity oil is applied to the airspace between slide and objective, the high viscosity oil is applied between the condenser and the slide.

How to Use it: Type A – Low Viscosity Oil

The majority of applications require Type A oil, which can be used as follows:

  1. Locate a specimen on the slide and center it in the image field.
  2. Rotate the nosepiece until the 100x objective lens is just to one side of the slide. Place a single drop of immersion oil on the slide cover slip and place a drop directly on the objective lens. Combined, both drops ensure no air is trapped in between.
  3. Rotate the 100x objective into place and adjust the fine focus to fully resolve the image.

Cleanup

It is very important to carefully clean the oil off your objective lens before it dries.

  1. Carefully wipe oil from all glass surfaces with a folded piece of clean lens paper.
  2. Moisten a piece of lens cleaning paper with lens cleaning fluid and wipe away any residual streaks of oil.

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Apr/13

23

WHAT EXACTLY IS MICROSCOPY?

You don’t have to be a science whiz to know your way around a microscope; if you completed high school science, it’s highly likely that you used a basic compound microscope to examine plant cells or the body of a flea. Perhaps you have a child who is clamoring for a microscope of their very own, or you’re a student facing a new semester of advanced science classes. Whatever your experience, it’s undeniable that microscopes are a fundamental part of the study of life sciences; they are used in a mind-bogglingly wide variety of ways across many different disciplines.

‘Microscopy’ is the study of objects that are too small to be seen with the naked eye, using a microscope to enlarge the desired image or sample. While many people can (and do) use microscopy principles every day, there are specialized microscopists who dedicate their lives to exploring the minute structures and properties of various materials. It seems like a very simple definition, but give it a little thought and you’ll realize just how multifaceted microscopy can be. In general there are three major branches of microscopy: optical, electron, and scanning probe. Each of these fields use different devices, and can accomplish very different things.

Optical Microscopy

The average high school graduate is likely familiar with optical microscopy; it’s the branch that uses a series of lenses and visible light sources to magnify a sample. Your high school biology lab probably used a standard compound microscope to study cell structure. Optical microscopes can be as simple as a handheld magnifying glass; the multi-lens compound microscope was invented in the 17th century, and has been extremely useful ever since. While optical microscopy is familiar, its importance shouldn’t be downplayed; the invention of the magnifying lens resulted in a seismic shift of humanity’s understanding of the world. No one realized the multitude of creatures and materials that existed alongside us, every day, too small to see with the naked eye. Optical microscopy allowed us to see bacteria, understand cell biology, and diagnose illnesses — and it’s still widely used all over the world today.

Electron Microscopy

Unfortunately, all optical microscopes have a resolving limit: a point of high magnification when the microscope just can’t resolve an image clearly. In the early 20th century, it became clear that some structures were too small to be affected by visible light sources; in these cases, scientists required a light source with a much smaller wavelength, like a beam of electrons. Electron microscopes were first patented in the 1920s; compared to the 2000x magnification power of an optical microscope, an electron microscope can achieve up to 10,000,000x. Electron microscopy is used to study crystals, cells, and large molecules. While they are expensive to build and maintain, these incredible machines have further revolutionized our understanding of the natural world.

Scanning Probe Microscopy

The third branch of basic microscopy goes beyond even the electron microscope, delving into structures at the atomic level itself. Scanning probe microscopy was developed in the 1980s, based on  quantum mechanics, and its imaging power makes an electron microscope look like a pair of blurry bifocals. Scanning probe microscopy forms images by using a physical probe, which can resolve differences at levels of tenths of nanometers; at the right resolution, you can see individual atoms within a sample. This is the newest form of microscopy, and scientists are just barely discovering its potential.

As one can see, microscopy covers a huge range of disciplines, magnifications, and potential applications. Every time we’re able to clearly see the building blocks of life, we learn more about who we are as a species and how the world works. Microscopy, as a field, manages to combine many disparate themes into one streamlined, incredibly rich scientific methodology.

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A microscope can change a student’s life forever and introduce your child to the smallest wonders of the world around him or her. But microscopes aren’t toys; even the simplest student-oriented device contains some very delicate parts. It’s important to learn how to handle and care for your new microscope properly, so that you can enjoy your device for years to come. Here are a few basic do’s and don’ts for two of the most important parts of a microscope: the illumination source and the lenses.

Light Sources
Light microscopes need a light source to illuminate the sample you are viewing. Modern microscopes typically employ tungsten, halogen or LED light bulbs. Field microscopes can employ ambient light although the first rule is never to use your microscope outside in direct sunlight as it can damage your eyes.  Halogen microscope bulbs can become very hot to the touch. If you need to replace the light source, turn off the microscope first and unplug it; this will allow the bulb to cool and prevent possible electric shock. Always use the correct light bulb; different brands require different bulbs that are calibrated to work with the lenses, so trying to swap out one type for another may cause damage to the microscope. Use your microscope in a well-lit room, and always place it on a flat surface.

Lenses
The lens of a microscope is the engine of the microscope. without it, your magnification efforts are futile. Compound microscopes have two types of lenses: the eyepiece, or ocular, which is what you look through; and the objective lenses, which are the primary magnifiers and are typically positioned directly above the stage on which the specimen will sit. Most compound microscopes include between three and five objective lenses that are mounted on a rotating turret. Magnification is achieved by multiplying the value of the eyepiece by that of the objective lens. For example, a 10x eyepiece and a 100x objective lens creates 1,000x magnification.

All microscope lenses are delicate and should never be touched with bare hands. If the lenses have dust or oil on them, clean with special lint free, lens tissue and a microfiber soft cloth. Neither of these will scratch the glass the way normal tissue paper would. Lenses can be damaged through improper cleaning techniques so it is important to use correct materials and if necessary. Begin by blowing away any dust using compressed dry air; there are some high-grade canned air products made specifically for optical equipment.  Moisten the lens tissue with a solvent-free  lens cleaning fluid and never dry wipe the glass.

Some microscopes use immersion oil, which reduces the amount of light refraction and provides a clearer image of the sample. This technique is achieved by immersing both the objective lens and the specimen slide in the oil. Always make sure to clean all of the oil from the slide and the lens once you are finished; any leftover residue can flow into the microscope casing and damage its components. Follow the instructions for oil immersion, carefully and clean all areas that have come into contact with the oil.

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Omano EZVU-2 tablet microscope cameraLook out for our new touch screen, OptixCam EZVU-2 tablet microscope camera. It will be ready for shipping in May 2013 and is an exciting addition to the OptixCam range of microscope cameras.It will work on any compound or stereo microscope with an appropriate adapter.

The EZVU-2 is a 2 megapixel digital microscope camera with integrated 8″ LCD tablet. Complete with touch screen and vibrant color resolution (1024 x 768 pixels), it has a hefty 5GB of internal storage and flexible output direct to the LCD screen, via HDMI cable to TV( or monitor), via the mini or standard USB ports to your computer or you can store images on the 2GB included microSD card.

In other words, while it operates on the Android OS, it is ‘computer agnostic’ in the sense that you can transfer images to either PC or Mac computers. The Android OS gives it both a touch screen and the ability to use a computer mouse.  We recommend the latter when executing sensitive  measurements in order to reduce any vibration caused by screen touch.

A Launch Alert will follow when we have a specific shipping date. In the meantime, please share this news with your colleagues.

 


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Has anyone else noticed the increasing number of microscope websites that advertise compound microscopes with mechanical stages….when in reality they are selling them with inferior mechanical slide holders? We think you should know the difference.

Mechanical Stage: A mechanical stage is integrated to any professional microscope.  In other words, it is standard operating equipment for any regular microscope user – which in itself speaks volumes. Typically, double-layered, a mechanical stage provides a stable slide platform and provides more precise movement of the microscope slide without the need to raise your eyes from viewing the specimen. This is important for any type of regular user since it makes for a significantly more seamless user experience.  Less hassle = more productive and enjoyable experience.

The structure of a mechanical stage includes a large hole to enable light from the condenser to pass through and includes drop down, right-hand coaxial controls. It is these coaxial controls that enable the ‘eyes-down’ operation. Often left-handed controls are also available.  Standard mechanical stages include a spring loaded slide holder  integrated into the design and XY axis that include graduated locator markings for precise movement of the slide.

Mechanical Slide Holder: A mechanical slide holder is a small and simple, spring  loaded slide holder that can be attached by screws on to a plain microscope stage.  While strictly speaking, it might be referred to as a microscope stage, microscopy professionals commonly differentiate it  by calling it a mechanical slide holder. A good analogy is a motorcycle.  Strictly speaking it is a motor vehicle, but no one thinks of it as such and it would be misleading to sell it as such.

Anyway, a mechanical slide holder includes two small knobs that enable X/Y movement with limited graduated locator markings.  These control knobs are separate for X and Y motion, are a fraction of the size of a mechanical stage and require you to look up from the specimen.  They are, in other words, somewhat awkward to use. They can also work loose over time.

As a result, these slide holders are designed for younger microscopists or where budget is limited. Budgetary constraints are understandable but we are not convinced about the argument around kids. In our opinion, kids needs to be engaged as easily as possible with a microscope – as with nay new learning experience.  This includes engaging subject matter and a hassle free environment. Otherwise, they are less likely to continue their interest.

The problem with a compound microscope is that young children often find slide specimens somewhat abstract (ie less engaging). When you layer on more hassle in using a cheaper microscope, in this case with a mechanical slide holder, you are decreasing the chance of sustaining their interest and attention.

We always recommend a mechanical stage if budget allows for anyone with a more sustained interest in microscopes. Either way, at least now you will be able to make a more informed purchase!

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The OptixCam OCS-10.0, ten megapixel, digital microscope camera has arrived and is working well. For the first time, it is Mac compatible although not with the full OC View software. The camera includes a Micron MT9P001 1/2.3 inch sensor with improved performance over its predecessor OCS-9.0. Faster 3 frames/second refresh rate at full resolution and up to 25 fps at 1280 x 1024 pixels.Priced at $499 with the normal free post sales service from Microscope.com makes this an useful addition to the OptixCam line up.

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We are pleased to announce that all of our OptixCam Summit series cameras are now fully compatible with Microsoft’s new Windows 7 operating system. We have gotten excellent feedback from these cost effective, high quality microscope cameras from our customers! Click here to check them out for yourself…

http://www.microscope.com/microscope-cameras-optixcam-c-31_116.html

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We are now launching the updated version of the OCS View software for our OptixCam USB digital microscope cameras and it is looking good!We have been selling OptixCam cameras for almost exactly one year, now, with strong feedback. Happily, these cameras perform significantly better than the Scopephoto software or Oplenic cameras which account for the majority of cheap microscope cameras on the market – and which we stopped selling last year.

Let us know your views on OptixCam cameras, please!

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The holidays are almost here. Don’t you think it’s time you got your hands on a Trekker microscope? Of course it is! The Trekker is a nifty little handheld microscope that is surprisingly powerful, given its size and portability. Endorsed by the Royal Botanic Gardens, the Trekker is great for viewing insects, pond scum, coins and stamps. It’s also a great introductory microscope for kids. They will have fun toting around the Trekker microscope on their adventures in the back yard and elsewhere.

We are offering the Trekker for $79 this holiday season. And it comes with an edible cricket lollipop!

Trekker Microscope

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It’s real. And it’s edible. Ewww, and it’s kind of gross!

See the rest of our stocking stuffers!

Cricket Lollipop

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What are you getting your child for Christmas this year? A Wii? “Guitar Hero”? An iPod? How about a digital microscope camera that is small enough to fit in his hand? The Dino-Lite digital microscopes have been flying off the shelves since their entry into the microscopy world, making them the “IT” item to have right now.

We just posted a selection of holiday specials that run the gamut at microscope.com. We are offering everything from compound microscopes for kids to Dino-Lite digital microscopes to research-grade binocular microscopes for medical students and more experienced microscopists.

Many of these holiday specials are bundled with prepared microscope slides,  Usborne’s popular book “The World of the Microscope,” and some even come with an innovative “specimen” — an edible, grape-flavored cricket lollipop! Farm-raised in the USA and sugar-free, your kid can view and photograph the lollipop … then EAT it!

Cricket Lollipop

View all of our holiday specials here.

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The Dino-Lite handheld digital microscopes have become very popular over the last few months. I noticed when posting the products to Microscope.com that it can get a tad confusing trying to distinguish between the various models available. To help decide which Dino-Lite might be best for you, I put together a handy FAQ specifically to address that question.

Check out the Dino-Lite FAQ here. If you have questions, don’t hesitate to contact us, either by commenting here on the blog or via e-mail at [email protected].

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Even though kids today are obsessed with the Wii or playing “Rock Band,” it’s nice to know they still get captivated by science. Sure, I was all about my Atari 2600 and “Mrs. Pac-Man” back in the 1980s, but I remember well my Rock Tumbler, ant farm and various Chia pets. Science was (and still is) a lot of fun.

Atomic Elephant Science & Toy Co. released its list of the 12 best-selling toys of 2008.  Among the top toys is Fly Trap Friends, Blizzard in a Bucket and Ant Jungle. Hey, it looks like the ants have finally left the farm!

Today we introduced our Halloween special at Microscope.com. We’re offering an entry-level, elementary school microscope with our “Creepy Crawlies” slide kit and a microscope book for $119. While we understand that Halloween is a time for candy and not necessarily gift-giving, why not invest in this deal for your child? One thing’s for sure … it won’t rot his teeth out and he’ll probably love it.

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Check out popular techie Chris Pirillo playing around with the Dino-Lite digital microscope on his show, Chris Pirillo Live.

“Would You Buy a USB Microscope?”

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Omano OM9949From  now through Sept. 30, if you purchase any school microscope from microscope.com, your school will automatically be entered to win the Omano OM9949 microscope, valued at $769.

Read more about it and sign up now.

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