Aligning the Condenser on a Biological Microscope

Biological microscopes are excellent for research, schools, and laboratories. The condenser should always be kept lint and fingerprint free for the clearest image. To clean the condenser it is best to remove it from the stage with a small screwdriver.

Once the condenser is unscrewed you can clean it and recenter it for optimal viewing. The center of the condenser is indicated with small perforated dots to help the end user align the condenser with the optical axis. If the sub-stage iris is also attached, which is fairly common with biological microscopes, then centering can be achieved by aligning the microscope objective on a low setting.

The sub-stage iris diaphragm should allow for a specific level of light to enter through the condenser thus illuminating the specimen and avoid over exposure. This will ensure proper exposure and resolution of your image and help ensure quality image and video every time you use your OMAX microscope. 

Why Choose Fluorescence Microscopy?

   Compound microscopes are primarily used today to focus on sequential focal planes. The translation of 2D and 3D has always been a roadblock in biology. As we all know, life is three dimensional and so biology should be studied in a three dimensional realm.

    Light microscopy, otherwise known as fluorescent microscopy has provided insight into a three dimensional cellular structure through light optics. The major downfall to this procedure is that only specimens must be composed of the thinnest samples in order to be visible in a good image.Fluorescence has since fixed the flaws of traditional light microscopy by offering higher resolution and light from axial focal plans.

Shop EPI-Fluorescence Microscopes: http://bit.ly/18laNsk
Shop Compound Microscopes: http://bit.ly/Vlkp12

About OMAX Microscopes

OMAX microscope is a Korean microscope manufacturer that has grown in popularity in recent years for its reasonable price point but quality design and features.

MicroscopeNet.com is proud to offer OMAX microscopes and believes in their capabilities of becoming one of the nation's leading microscope manufacturers. OMAX has high quality optics and accessories. OMAX is also highly customizable with kits to add brightfield and darkfield illumination features to a stereo or compound microscope.

We recommend checking out their selection of digital microscopes which will enable you to take videos and images with your OMAX microscope and software that is included in the package. 

Check out our video using the OMAX M82ES Lab LED Binocular Compound Microscope.

Brightfield Illumination Microscopy

The great thing about purchasing a bright-field microscope from MicroscopeNet is that it has a built in illumination that will directly reflect light onto the slide. Bright-field microscopes are great for observing stained samples that absorb larger areas of light. They are also excellent for observing naturally stained samples that allow a lot of light to reflect through.

The total bright-field system utilizes light from an lower source that allows the user to view magnified objects through an ocular lens. The condenser lens below the stage will direct the light through the specimen, making for a highly detailed image. This form of microscopy is best  for microbiology and botany. 

We recommend the Brightfield & Darkfield Kohler Microscope with 9.0 USB Camera 

Browse: http://bit.ly/19AzLTD

Safety Tips in Microscopy Pt.1

There is a ton of articles and instructions for taking precaution steps when handling solvents and stains. Much less is discussed when it comes to taking precautions about handling organisms themselves. Below is general advice to adhere to when handling samples that contain microorganisms.

Image: http://www.fscjinstituteforfoodsafety.org/

1. Open wounds:
Do not handle microorganism-containing media if you have open wounds or cuts in your skin.

2. Disinfection:
Always disinfect hands and surfaces with an anti-bacterial cleaning agent.

3. Disposal:
Autoclave the used culture medium at 120°C for 30 minutes. This should also be able to kill spores. If you do not have an autoclave available, then cover the petri-dishes or culture medium with chlorine bleach. Allow sufficient time for these substances to work. When you add bleach, be aware that this is a corrosive substance when concentrated. Eye and skin contact must really be avoided.

4. Avoid Aerosolization:
Some microorganisms spread over air. Avoid spillage of the culture medium and carefully add the disinfectant to the medium before disposal, avoiding splattering of the liquid.

5. Keep Bacterial Counts Low:
Make sure that the sample (such as a hay infusion) contains many ciliates that consume the bacteria. Keep the level of nutrients low to avoid too many bacteria from forming and ensure that the medium has sufficient oxygen supply for the ciliates to grow.

Keep petri dishes closed and sealed. This minimizes the risk of accidentally touching the agar surface, which may be covered by bacterial colonies. Being aware of your work space and the risks of the chemicals used can reduce the possibility of you encountering risks from working with bacteria specimens.

Image: http://www.fscjinstituteforfoodsafety.org/

Uses for Digital Microscopes

A digital microscope is the combination of a standard light microscope with a digital camera and accompanying software. The advantage of using a digital microscope is the ability to display images of the specimen on a computer monitor or TV screen and then save them as either still images or motion video to a hard drive.

Below are examples of excellent used for digital microscopes: 
1. Media taken with a digital microscope allow you to accurately measure, manipulate and study the subject matter on a much larger scale.
2. Media taken from digital microscopes can be used in reports, presentations, or assessments. They can easily be shared through email, across the web, or in lectures with colleagues or students. One digital microscope eliminates the need for one microscope per student because the same image can be viewed by the entire class when it is projected onto a screen.
3. Digital microscopes are useful in a variety of different fields such as biology, chemistry, and earth science. Low power digital microscopes are used frequently in gemology and manufacturing.
4. Digital video microscopes provide the ability to view small parts on large screens thereby reducing eye straining. These are extremely useful for the quality assurance team of manufacturing facilities.

Digital microscopes are perfect for any inspection services where constant examination of small parts is mandatory. Digital stereo zoom microscopes, also known as industrial stereo microscopes, are preferred by quality control labs and in fields of study such as petrology, gemology, and even numismatics.

Fluorescence Microscopy Tips

The images you take are only as good as your equipment. So take time to take care of your equipment on a regular basis; clean objectives, cover slips, and ensure your microscope has the proper setup.

Most objectives are designed for a cover-slip that is .17mm thick. If you fail to use the proper cover-slip, you will lose image clarity and sharpness. Although cover-slip thickness can range anywhere from .08mm to .25mm in thickness, .17mm is the most common and optimal for most microscopes.

Slides are also another component that vary in quality. Research your brands and find out which is the best for your type of microscope.

For further tips we recommend referencing the following text:
"A Guide to Super-Resolution Fluorescence Microscopy" (2010) Schermelleh et al. J Cell Bio.
"Live Cell Microscopy- Tips and Tools" (2009) Frigault et al. J Cell Sci.

Back to School Tips

It's once again that time of year for students. A time of new classes, new teachers and an entire year of learning and discovery for students as a new school year is in their horizon. Below are some helpful tips for keeping your student organized and focused all school year long. 

Use binders for organizing projects or subjects. Create a science binder that you will fill up all year long with images and projects.

Create a science storage area where the kids can access supplies when needed, but also know how to put scientific instruments away to protect them. If you have a microscope, store it in a case, or keep the microscope dust cover on it when not in use. 

Shop Carrying Cases: http://bit.ly/VFEOjM

Create hands-on experimental learning experiences at home. Make an effort to take children on after school educational outings and talk to them about their learning experiences. Reinforcing what they have learned in school is an excellent way to sharpen their skills in science. 

Shop Student Biological Microscopes: http://bit.ly/15eWdjY

For beginning science students we recommend the:

40X-1600X Digital Monocular Compound Microscope with 1.3MP Camera

On sale for $259.99 USD

Shop: http://bit.ly/YNBlAA

Immersion Oil 101

Immersion oil is used with high power objectives such as light microscopes.

Light microscopes have an upper limit to their resolving power of marginally over 1,000 x. At this level of magnification, the microscope needs to direct every available amount of light in order to achieve a clear image. 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.

Shop Immersion Oil: http://bit.ly/14WDn5l

Immersion oils are commonly available in two viscosities; low viscosity (A), and high viscosity ( B). 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: Locate a specimen on the slide and center it in the image field. 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. 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. Carefully wipe oil from all glass surfaces with a folded piece of clean lens paper. Moisten a piece of lens cleaning paper with lens cleaning fluid and wipe away any residual streaks of oil.

Polarizing Microscopes

Several types of microscopes are at hand for study of biological materials. Their classification is based on the types of light source used and consists of two main categories; optical microscopes utilizing visible light and microscopes that utilize sources other than visible light. 

Polarizing Microscope: Many natural objects including crystals & fibers exhibit special optical property known as double refraction or birefringence. Birefringence is caused by asymmetric particles, too small to be resolved even by best possible lenses. The polarizing microscope is a conventional microscope in which a nickel prism or Polaroid sheet is interposed in the light path below the condenser. This polarizer converts all the light passing through the instrument into plain polarized light. A similar second prism know as the analyzer is placed within the barrel of the microscope above the objective lens. When the analyzer is rotated until its axis is perpendicular to that of polarizer, no light can pass through the ocular lens, resulting in a dark field effect. The field will remain black if an isotropic or singly refractive object is placed on the stage. A birefringent object, however, will appear bright upon a dark background when examined in this manner.

Shop Polarizing Microscopes: http://bit.ly/Xy5y2N

We recommend the 40x-1000x Trinocular Infinity Polarizing Microscope with 9.0 MP Camera

Shop: http://bit.ly/19tAQRO

Objective Lens Comparison

Objective Lenses: 
Achromatic vs Semi-Plan vs Plan 

Besides some special microscope objective lenses, there are three kinds of objective lenses on the market.
Achromatic, semi-plan, and plan. 

Achromatic Lens:

Semi-Plan Lens:

Plan Lens: 

 

First of all, all these three objective lenses correct for color, although there's no "achromatic" in the name of "semi-plan" or "plan". The difference between these three lenses is the focusing area which can be seen from the eyepieces when using high power objective lenses such as 40x, 60x and 100x. 

The difference from low power lenses are not obvious, which means that can be ignored. At high power, an achromatic lens has about 65% of focused area acrossing the center. A semi-plan one has about 85% whereas the plan one has 95%. 

 Due to the correction from the different lenses, the price for those lenses are also different. Here are some links for the objective lenses: 

Achromatic: http://www.microscopenet.com/achromatic-objective-lenses-compound-microscopes-p-377.html 
Semi-Plan: http://www.microscopenet.com/semi-plan-achromatic-objective-compound-microscopes-p-317.html
Plan: http://www.microscopenet.com/plan-achromatic-objective-compound-microscopes-p-316.html

Live Blood Analysis: Leukocytosis

We were testing out some blood specimens yesterday we used a methylene blue I was testing some mountants for peripheral blood smears.
Stain used: methylene blue, polychromed by boiling with Na2CO3 for about 30 minutes. The smear was heat-fixed, brought to alcohol and then xylene, and finally covered with mounting medium and a cover slip. Thick smear leukocytes

 The CMOS eyepiece camera is a great way to get micro-critters onto a video screen, but it doesn’t show quite as much detail as the human eye can see looking through the eyepiece. However, you can see from the photo that there appears to be a mix of immune-response cells.

 On another note, you will notice there are no erythrocytes visible. The polychromed methylene blue is normally treated with eosin to give a Romanowsky stain; this reveals both red and white cells. The white cells’ cytoplasm collapsed or degraded severely in both test specimens after about a week, except in those areas where it was apparently stabilized  in the thicker regions of the smear.

The History of the Microscope

During that historic period known as the Renaissance came the invention of the light microscope. A revolutionizing instrument that enabled the human eye to observe microscopic objects. It enabled people to understand the fascinating details of the known world.

In 1590, two Dutch spectacle makers discovered that nearby objects appeared greatly enlarged. That was the forerunner of the compound microscope and of the telescope. In 1609, Galileo, father of modern physics and astronomy, heard of these early experiments, worked out the principles of lenses, and made a much better instrument with a focusing device.

The father of microscopy, Anton van Leeuwenhoek, started as an apprentice in a dry goods store where magnifying glasses were used to count the threads in cloth. He taught himself new methods for grinding and polishing tiny lenses of great curvature which gave magnifications up to 270 diameters, the finest known at that time. He was the first to see and describe bacteria, yeast plants, the teeming life in a drop of water, and the circulation of blood corpuscles in capillaries. He studied both living and non living, and reported his findings in over a hundred letters to the Royal Society of England and the French Academy.

Anton van Leeuwenhoek Microscope

(Via birthstory.com)

Robert Hooke is considered the English father of microscopy because he confirmed Anton van Leeuwenhoek's discoveries of the existence of tiny living organisms in a drop of water. Hooke made a copy of Leeuwenhoek's light microscope and then improved upon his design.

Robert Hooke Microscope 

(Via http://micro.magnet.fsu.edu/primer/museum/hooke.html)

A Microscope Master Review

Review: 

OMAX 40X-2000X Digital Binocular Biological Compound Microscope with Built-in 3.0MP USB Camera and Double Layer Mechanical Stage

"The construction and all round capabilities of this microscope surpass what you would normally expect for this price. 

 This Omax microscope offers affordability, convenience and durability. Images obtained are bright and clear, controls are firm and the stage and slide holder are easy to work with. 

 Equipped with a 3.0M pixel built-in USB camera, you will enjoy not only photo capability but video as well which is especially beneficial where participation in a group setting is necessary. 

 Pictures can be brightened, cropped and saved easily. 

 It is compatible with MS Windows 2000/XP/Vista as well as Windows 7 -32bit and 64bit. 

 Worth noting is Omax's excellent customer service and informative technical support."

Shop Model: M827S-C30

Cell Staining Simulation Tool

We recently discovered an amazing new tool from www.invitrogen.com.

Stain your own cell by using cell staining simulation to develop amazing results with their florescent dyes. 

Try it here: http://bit.ly/blBLo5

Before Stains

After Applied Stains

Living Cell Microscopy

Live cell microscopy is now a very common form of research in many fields in life science and other physical sciences. Live cell microscopy is crucial when performing experiments where cell visibility is at the center of measurement to ensure that biological processes are not altered in anyway.

 

Most cells and tissues are never exposed to sunlight so proper microscopy procedures that minimize light exposure. To ensure minimal light exposure, microscopes should be optimized to collect as much of the light source as possible.

 



 

 

It is crucial to ensure suitable environmental conditions on the microscope stage to maintain living cells. With an efficient optical microscope and detector, the light exposure can be minimized during live cell imaging, thus minimizing phototoxicity.

 

Perfect for Live Blood Analysis:

5.0 MP Digital Darkfield Siedentopf PLAN Microscope

(40X-1600X) $1,199.99

Shop here

Uses for Darkfield Microscopy

Darkfield microscopy allows for beautiful, detailed images to be revealed with one opaque disk used to block the light into just a few scattered beams. The background is dark and the sample reflects the light of the beams only. This results in a light colored specimen against a dark background. Darkfield microscopy is perfect for viewing clear or translucent details.

When to Use a Darkfield Microscope:

• Single- celled organisms
• Live Blood Analysis
• Transparent Specimens
• Live Bacteria
• Soil Samples
• Pond water Bacteria
• Seawater Samples
• Pollen Samples

Darkfield microscopy make most invisible specimens appear visible under the microscope, especially living organisms. 

Shop Darkfield Microscopes: http://bit.ly/11Rl53o

How to Set Up a Phase Contrast Microscope

Phase contrast is a microscopy technique that is helpful in viewing many biological specimens such as bacteria or blood cells. When setting up your phase contrast microscope, you must have phase contrast objective lenses and a phase contrast condenser.

The condenser shown above has five settings on it: 10x, 20x, 40x, 100x and bright field. The two screws that stick out from the condenser are centering screws and will be used when you set up the phase contrast microscope for the first time.  Set the condenser on the bright field setting and focus on a specimen. Adjust the height of the condenser for optimum image quality. Move the condenser turret to the phase setting for whichever lens you are currently using and remove the specimen.

Remove one of the eyepiece lenses and insert the centering telescope in its place. If there is a set screw on the side of your centering telescope this should be used to focus the centering telescope. When looking through the centering telescope you will see two rings. By turning the centering adjustment screws on the condenser, you can align the rings so they are concentric.

Remove the centering telescope and replace the eyepiece lens. Put your specimen back on the stage and you are ready for phase contrast observation! You will want to go through this process when you change objectives.

Shop Phase Contrast Kits: http://bit.ly/11Rn0yh

Ultra Violet Lights

Ultraviolet light also referred to as UV light can be used as a germicidal agent to sterilize surfaces where sensitive microbiology techniques are being performed. UV light is non-ionizing short wavelength radiation that falls between 4-400 nano-meters in the visible spectrum.

In general, the shorter the wavelength the more damaging it is to cells which makes UV light more damaging than visible light or infrared light. Most bacteria are killed by UV light. UV radiation at 260 nm is most damaging because at this wavelength DNA maximally absorbs UV light.

When DNA absorbs UV light pyrimidine dimers form.  These dimers distort the overall structure of the DNA strand and prevent DNA polymerase from moving past the dimer. Genes downstream from the dimer will not be transcribed and essential proteins will not be formed.

The ability of the organism to function normally will be affected by the formation of one dimer. Ultraviolet light kills cells by damaging their DNA. The light initiates a reaction between two molecules of thymine, one of the bases that make up DNA.  Even so, it breaks down when the damage is extensive.

Tips for Caring for Your Microscope

Microscopes are delicate pieces of equipment, so you should follow a few basic rules to prevent damage to the microscope.

These rules are meant to prevent you from dropping the microscope, from damaging the lenses, or from storing the microscope improperly. Dropping a microscope can break the lenses or can alter the alignment of the lenses. To prevent this damage, you should always carry the microscope with two hands; one hand under the base and the other hand on the arm of the microscope. 

When using the microscope, keep the instrument at least six inches from the edge of the lab table and keep any excess electrical cord on the table top to keep the microscope from being pushed or pulled off the table. The microscope's lenses are very delicate and can easily be scratched or damaged by oils. Lenses should be cleaned before and after each use with special lens paper. In addition, you should refrain from touching the glass lens with your finger to avoid depositing oils or scratching the glass. 

When using the microscope to view a specimen, you should follow common sense rules of behavior. Do not tamper with any part of the microscope unless you understand its purpose. A common mistake is to focus quickly while looking through the eyepiece of the microscope so that the objective lens bumps into the slide. To prevent damage to the lens, you should always make large focus changes slowly while observing the movement of the objective lens from the side of the microscope. 

Finally, the microscope should be stored carefully. Unplug the electrical cord by pulling on the plug instead of the cord. Remove oil from the oil-immersion objective using lens paper, then turn the nose piece so that the low-power objective is in place. Carefully lower the objective to its lowest position by turning the coarse adjustment knob. Then store the microscope under a dust cloth.

Microscope Basics for Beginners

Introduction 

 Microorganisms, as their name implies, cannot be seen with the naked eye. Although they were observed as early as 1674 by Anton Van Leeuwenhoek using a simple, single-lens microscope, it was not until the development of the modern compound microscope that the real diversity of microorganisms became apparent.

There are two basic categories of microscopes: light microscopes and electron microscopes. Light, or optical, microscopes require light waves to provide the illumination while electron microscopes use electrons to provide the illumination. Light microscopes are used for most general laboratory work, while electron microscopes are used to view extremely small objects such as sub-cellular components or viruses. In each basic category of microscope, there are a variety of sub-types. Light microscopes may be bright field, dark field, phase contrast, or fluorescence, while electron microscopes can be either transmission or scanning. The most commonly used laboratory microscope is the bright-field microscope, so this lab will be concerned exclusively with bright-field microscopes.

 PARTS OF A MICROSCOPE:

• Base Supports the microscope 
• Light Source Illuminates the object to be studied 
• Iris Diaphragm Controls the light intensity on the object 
• Condenser Concentrates light on the object 
• Stage Platform which supports the slide containing the object to be studied 
• Arm Carrying handle 
• Coarse Adjustment Knob Large outer knob which brings the image into rough focus 
• Fine Adjustment Knob Small inner knob which brings the image into clear focus 
•  Low Power Objective Magnifies the object ten times (10×) 
•  High Power Objective Magnifies the object 43 times (43×) 
•  Ocular Lens Magnifies the image produced by the objective lens ten times (10×)
•  Revolving Nose piece holds the objective lenses and allows you to change directly from one objective to another without having to refocus Basically, the microscope consists of a support system, a light system, a lens system, and a focusing system.  Each of these systems works together to produce a magnified image of the specimen. 

 Support System 

The support system consists of the base, arm, and stage. The base and arm are structural elements which hold the other parts of the microscope in place while the stage holds the slide. Depending on the microscope, the slide can be positioned under two spring clips and moved by the fingers, or it can be held in place by a mechanical stage and moved by means of two control knobs.

1.  Light System The light system passes light through the specimen using the light source, the condenser, and the iris diaphragm. In a bright-field microscope, an incandescent bulb is usually used as the source of illumination. Light from the light source then passes through the condenser which focuses the light on the specimen. 
2.  An iris diaphragm is used to control the intensity, or brightness, of light which passes through the specimen, thus allowing the operator to adjust the intensity and achieve an optimum viewing contrast.

Lens System 

 The lens system forms the actual image which you will see when you look through a microscope. A typical compound microscope has two lenses - an objective lens near the specimen and an ocular lens at the top - each of which magnifies the image of the specimen by a certain amount. The ocular lens on most microscopes magnifies 10x. In contrast, the typical microscope has at least three objective lenses mounted on a revolving nose piece to allow for different magnifications.  There is a limit to the amount of useful magnification one can achieve with a light microscope. The highest magnification which can be achieved without producing a poorly resolved image is known as the resolving power of the lens. The resolving power is the shortest distance between two closely adjacent points which can be seen and is based on the wavelength of light used for illumination and on the nature of the lens.

 Focusing System

The final system at work in the microscope is the focusing system. So far, we have learned how all of the components of the microscope are held together by the support system, how the light system sends light through the specimen, and how the lens system uses that light to magnify the specimen's image and transmit it to our eyes. The focusing system adjusts the distance between the slide and the objective lens so that the image comes into focus. The focusing system consists of two knobs - the coarse adjustment knob and the fine adjustment knob. When focusing, the operator first turns the coarse adjustment knob (which is the larger focus knob) in order to move the stage a large distance and bring the image into the focal plane of the objective lens. At this stage, the image will be visible but fuzzy. Then the operator turns the smaller knob, known as the fine focus knob, to fine tune the focus and to make the image sharply focused.