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