Friday, August 31, 2012

Cordless Field Microscopes

Cordless microscopes, sometimes referred to as field microscopes, are great tools for use in countries where electricity is limited, for performing work out in the field, or when using a microscope in a room that does not have an outlet handy. When teaching small children it is often nice to be able to use a microscope that does not have a cord connected to it, simply because children can trip on the cord or are more likely to knock the microscope off the table if the cord gets caught on something.

There are several types of cordless microscopes including stereo microscopes, biological microscopes and shop microscopes.

Cordless stereo dissecting microscope Swift 101.

Richter Optica F1 kids microscope
Cordless F1 student microscope.

Cordless shop microscope MW5-L1.
Shop microscopes are cordless and have an attached pen light for illumination. The microscope offers a single magnification (your choice of 20x, 40x, 60x or 100x) and a built-in measuring eyepiece reticle. This reticle imposes a ruler directly on the image you view through the shop microscope. Shop microscopes are typically used by tool makers or for viewing the quality of textiles.

Most cordless microscopes run on rechargeable batteries and can be operating while the microscope is charging. There are a few that still work with disposable batteries. If you are in the market for a cordless microscope be sure you figure out which type of battery you prefer prior to purchasing the cordless microscope.

Wednesday, August 29, 2012

Microscope Cleaning Kit

Keeping your microscope clean and in working order is essential for getting the maximum years of use out of your scientific instrument. Gathering the correct supplies for optimal cleaning can be time consuming. Therefore, Microscope World has assembled a cleaning kit with all the items you might need to keep your microscope functioning.

Microscope cleaning kit.
The microscope cleaning kit contains the following:
  • Soft lens brush - best for eyepiece and objective lenses.
  • Cleaning cloth - highly absorbent for water, grease, oil or other liquids.
  • Instrument microscope body cleaner - safe, fast and effective cleaner for the microscope body. Anti-static and leaves no residue.
  • Cleaning swabs - lint-free and ideal for cleaning any hard-to-reach areas on the microscope.
  • Lens wiping cloth - soft cloth for removing dirt and oil from eyepieces or objective lenses.
  • Lens cleaner - anti-static cleaner that removes dirt, dust and fogginess from lenses while creating a protective layer on lenses to prevent further residue build-up.
  • Air blower - Puff-of-air tool to gently blow dust off optics without having to touch the lenses. Ideal for preventing scratches on highly dirty lenses.
Click here for more tips on keeping your microscope clean.

Monday, August 27, 2012

Backyard Science

Finding interesting items to view with your stereo dissecting microscope is easy if you live near a pond or marshy body of water.

We recently visited a local lagoon to gather some interesting specimens to view under the microscope. Even if you don't live near a pond, look in your back yard for some stones, flowers and interesting leaf patterns to place under the stereo microscope.

This cattail was captured using a stereo microscope and the MW5.1 CCD microscope camera.

Cattails are also referred to as bulrush or Typha. Their rhizomes (stems) are edible and were consumed in Europe thousands of years ago. (We do not recommend eating them today). Typha is often among the first wetland plants to colonize areas of newly exposed wet mud, with its abundant wind dispersed seeds. It can also survive in the soil for long periods with buried seeds. It is considered to be a dominant competitor in wetlands, and often excludes other plants with its dense canopy. Muskrats are known to eat a lot of cattails.

Bee captured with the MW5-L5 stereo microscope using the MW5.1 CCD microscope camera.

Bees are located on every continent except Antarctica, and are known for their aid in pollination of flowers. Chances are that if you have flowers growing in your back yard, you will also at some point have bees as well.

What other items can you locate near your house to view under the microscope? What about a blade of grass or an interesting rock? Do you have a garden? If so, try looking at something from your garden such as the husk from an ear of corn or a slice from a fresh lemon.

Wednesday, August 22, 2012

Prokaryotes in the Ocean

Archaea are a group of single-celled microorganisms. Originally, Archaea were classed with bacteria as prokaryotes and called archaebacteria. However, after much research scientists discovered Archaea have an independent evolutionary history and show many differences in their biochemistry from other forms of life, so they are now classified separately in the three-domain system (or Phyolgenetic Tree of Life) as Archaea, Bacteria, and Eucaryota.

 Image of Archaea courtesy of NASA, US Government.

Bacteria and Archaea lack a nucleus, which is why they were originally lumped together under the name prokaryotes (before a nucleus).  Bacteria and Archaea have no organelles or membrane-bound compartments inside of them and are similar in that they can be difficult to distinguish from one another. Although often lumped together under the name Prokaryote, these two groups are only distantly related and each group performs very different functions.

In the ocean, Prokaryotes are abundant, with around 1 billion cells per liter of surface seawater. Prokaryotes can acquire energy to grow from a wide variety of chemical reactions or by photosynthesis. Photosynthetic bacteria (cyanobacteria) are the most abundant phytoplankton in the ocean. Prokaryotic cells range in size from 0.2 – 10.0 um.

Prokaryote Cell, image courtesy Mariana Ruiz Villarreal

Bacteria have four common cell morphologies: spherical, rod-shaped, spiral and comma-shaped. Most prokaryotes exist as individual cells, but some are filamentous or chain-forming.

 Bacteria captured with the MW4-HD1 digital microscope using phase contrast.

Prokaryotes have one or two cell membranes and may have flagella (thin whip-like filaments used to move about). Because Prokaryotes lack a nucleus or membrane-bound compartments inside of them, there is little internal structure visible by microscopy.

Monday, August 20, 2012

Comparing Biological Digital Microscopes

In this post we compare images captured with the Swift M10LB digital biological microscope against those captured with the Motic Digital BA310 microscope. The Swift digital microscope has a few features that differ from the Motic BA310 digital microscope, in that the Swift has a 3" LCD screen where you can view a live image on the microscope and capture that image directly to an SD card. (SD card is not included with microscope when purchased). The SD card captures 5 mega pixel images, whereas images captured with the included software are only 0.3 mega pixels. Although the Motic BA310 digital microscope does not have an LCD viewing screen, all images captured with the included software are 3 mega pixels.

Swift M10LB digital biology microscope.
Motic BA310 Digital Microscope
Motic BA310 digital biology microscope.

Each microscope was used with the exact same sample, and images were captured using the software that is included with the digital microscopes.

Human blood cells captured at 400x magnification with the Swift M10LB digital microscope.

Human blood cells captured at 400x magnification with the Motic BA310 digital microscope.

Bacteria captured at 400x magnification with the Swift M10LB digital microscope.

Bacteria captured at 400x magnification with the Motic BA310 digital microscope.

Each of these digital microscopes allows you to view a live image on your computer screen when the (included) software is open on the computer. Images can be captured and saved, annotated and emailed. Motion video can also be captured, as well as measurements made with the software. Email Microscope World with any questions regarding these digital microscopes.

Tuesday, August 14, 2012

Ocean Plankton and Its Various Sizes

Ocean life spans size from the largest mammal (the blue whale is 30 meters in length) to the smallest microorganisms roughly 20 nanometers across. Animals in the ocean that can swim quickly relative to the speed of ocean currents (squid, fish, turtles, whales) are classified as nekton, or swimmers.

Organisms that don’t swim, or swim very slowly relative to ocean currents are classified as plankton, or drifters. Plankton includes some larger sized animals such as the Lion’s Mane Jelly (2 meters across!), but most plankton consists of protists, bacteria and viruses that could not be collected with a net. Microscopic plankton are by far the most abundant life forms in the sea.

Plankton marine life can be organized into the following categories based on size.
Femtoplankton = 20nm – 0.2um
Picoplankton = 0.2 – 2um
Nanoplankton = 2 – 20um
Microplankton = 20 – 200um
Mesoplankton = 0.2mm – 20mm
Macroplankton = 2cm – 20cm
Megaplankton = 20cm – 2m

Bacteria is a form of plankton.
Plankton that you would view with a dissecting stereo microscope fall into the Mesoplankton class. Most of the plankton viewed with a high power light microscope are Zooplankton, as well as a few large Phytoplankton and Protists. The smaller plankton (micro, nano, pico, femto) require special microscopes such as scanning electron or epi-fluorescence microscopes in order to view them. The chart below shows the types of plankton, sizes and instrument required to view it.

Thursday, August 9, 2012

An Apple A Day

The apple tree originated in Western Asia. There are more than 7,500 known cultivars of apples, resulting in a range of different characteristics. Different apples are bred for various tastes and uses, including cooking, off-the-tree eating and cider production. Domestic apples are generally propagated by grafting, although wild apples grow readily from seed.

The illustration below shows some of the health benefits from human consumption of apples.

Illustration courtesy Mikael Haggstrom.

The center of the apple fruit contains five carpels arranged in a five-point star, each carpel containing one to three seeds, called pips.

Apple seed captured under a stereo microscope.

Apple seeds are mildly poisonous, containing a small amount of amygdalin, a cyanogenic glycoside. It usually is not enough to be dangerous to humans, but can deter birds from eating the fruit.

China is the number one producer of apples in the world, followed by the United States and Turkey.

Tuesday, August 7, 2012

Bed Bugs Under the Microscope

Bed bugs are parasitic insects that feed on blood - similar to mosquitoes. Bed bugs are primarily active at night and can feed on their hosts (humans) without being noticed. The most common problem humans humans face from bed bugs are skin rashes and allergic reactions.

Image of a bed bug captured under a stereo microscope by Winston Ingram. Bed bugs are typically best viewed at around 40x magnification. Most bed bugs are 4-5mm long.

 Mouth of a bed bug.

Bedbugs are very flat, allowing them to hide in tiny holes. A crack wide enough to fit the edge of a piece of thin cardboard card can harbor bedbugs. The most common place to find bedbugs is the seams of a bed, crevices of the mattress, box spring, bed frame and headboard.

Bed bugs are also known as louse, mahogany flat, crimson rambler, heavy dragoon, and redcoat. A recent increase in bed bug infestation is likely due to increased resistance to pesticides used to eliminate bed bugs.

Thursday, August 2, 2012

Microscope Field Size, Field Number & Field of View

When working with microscopes you have may have come across the terms field size, field of view or field number. This post will help explain each.

Microscope Eyepiece
The microscope eyepiece shown above is made by Motic. The text shown on the eyepiece is explained below:
  • N - Motic uses this letter to indicate a higher quality (such as a plan objective versus a standard achromat objective) of eyepiece lens.
  • WF10x - This is a widefield 10x eyepiece. 10x refers to the magnification of the eyepiece. Total magnification of the microscope is a combination of the eyepiece and the objective lens being used.
  • 20 - This is the field number, in this case the eyepiece has a field number of 20mm.
  • Eyeglasses - This image explains that these eyepieces are focusing eyepieces.
Field number is the diameter of the eyepiece lens and is most often expressed in millimeters.

Field of View (FOV) is the amount of the object that can be seen with a particular optic combination (eyepieces + objective lens). It is the circular area that is seen when looking through the microscope. The field of view decreases when the magnification is increased. For example, if you are viewing a coin and zoom in to see more details, you see less of the surface area of the coin. In most cases, you can use the formula below to determine the FOV or field size.

Field Size = Field Number ÷ Objective Magnification.

Remember when using the above formula that if auxiliary lenses are being used in addition to the microscope objective that they must be included in the objective magnification.