Tuesday, 29 July 2014

Do you like macro photography?

Do you like macro photography?
The macro lens included with any Moticam gives you endless opportunities…

Have a closer look at this sunflower using a Moticam 5 and a 12mm macro lens at different focus distances. You can see that the sunflower is in fact a composition of hundreds of individual flowers at different developmental stages.

Wednesday, 23 July 2014

Streptococcus, friend or foe?

Hemolysis (or haemolysis) is the rupturing of erythrocytes (red blood cells) and the release of their contents (cytoplasm) into surrounding fluid (e.g., blood plasma).

Streptococcus is a genus of spherical Gram-positive bacteria belonging to the phylum Firmicutes and the lactic acid bacteria group. Cellular division occurs along a single axis in these bacteria, and thus they grow in chains or pairs. Species of streptococcus are classified based on their hemolytic properties. Alpha hemolytic species cause oxidization of iron in hemoglobin molecules within red blood cells, giving it a greenish color on blood agar. Beta hemolytic species cause complete rupture of red blood cells. On blood agar, this appears as wide areas clear of blood cells surrounding bacterial colonies. Gamma-hemolytic species cause no hemolysis. In addition to streptococcal pharyngitis (strep throat), certain streptococcus species are responsible for many cases of pink eye, meningitis, bacterial pneumonia, endocarditis, erysipelas and necrotizing fasciitis (the 'flesh-eating' bacterial infections). However, many streptococcal species are nonpathogenic, and form part of the commensal human microbiome of the mouth, skin, intestine, and upper respiratory tract. Furthermore, streptococci are a necessary ingredient in producing Emmentaler ("Swiss") cheese.

Sepsis is a potentially fatal whole-body inflammation caused by severe infection. Sepsis can continue even after the infection that caused it is gone. Sepsis causes millions of deaths globally each year. Sepsis is caused by the immune system's response to a serious infection, most commonly bacteria, but also fungi, viruses, and parasites in the blood, urinary tract, lungs, skin, or other tissues.

Source: Wikipedia

Thursday, 17 July 2014

Basics of Light Microscopy II: Koehler Illumination

A high quality illumination is regarded as a key issue for a perfect information transfer from specimen to target (human eye/camera chip). The illumination angle, definable by the condenser diaphragm, directly affects the resolution power of the microscope system. The final illumination setup should create a homogenous image background with a high dosage of sample details “on top”.

Unfortunately the human eye is an incorrigible liar. It compensates illumination defects and pretends depth of focus. On the contrary, the microscope camera is brutally honest to a suboptimal setup and reveals any deficit in illumination. No coincidence that August Karl Johann Valentin Koehler (1866-1948) developed an optimized microscope illumination while working on photomicrography problems. 

Following A. Koehler, a perfect microscope illumination has to fulfil the following requirements:

  • The illumination aperture (=angle) should be adaptable to the NA (=opening angle) of the objective in use.
  • In order to reduce stray light, the illuminated object area should be definable.
  • Illumination aperture and illuminated area should be adjustable independently.
  • Illumination for each image point has to be identical.

Field and aperture diaphragm are the important variables of the microscope illumination and enable the user to follow Koehler’s requirements.

In Motic’s BA310 Elite, the necessary “hardware” can be found here:

How to do a proper Koehler setup? The first 4 steps have to be taken by using the field diaphragm:

The final adjustment has to be done with the aperture diaphragm:

Especially unstained specimen (native smears, water samples) require a stronger closure of the aperture diaphragm to achieve contrast, while stained histological sections are less demanding. The following chart may help to understand the consequences of the aperture diaphragm setup:

Using the aperture diaphragm will balance the image parameters (contrast, resolution, depth of field, brightness), always depending on the sample characteristics. Please do not use the condenser diaphragm to reduce the image brightness (do you place a brick on the fuel pedal of your car, while regulating the speed with the brake pedal?). The light setting in most cases is too high to observe delicate structures, be careful not to outshine them.

Take the best possible profit from the microscope hardware in front of you! Follow August Koehler, and you will install best preconditions for your maximal understanding of the sample.

If you wish, you can take a look to our video tutorial about how to adjust the Koehler illumination:

Wednesday, 9 July 2014

This flea does not stitch and itch

Daphnia, commonly called water fleas, are a freshwater zooplankton found in ponds and lakes all over the world. Daphnia received the name water flea due to their jerky swimming motions. Some types of Daphnia can be seen with the human eye, while others must be identified with a microscope. Depending on the species they can range in size from 0.5mm to 1cm. Their outer covering, or carapace, is transparent, so many internal organs can be seen, especially the beating heart. On the head there is a compound eye and a pair of antennae, which are used for swimming. Females are usually larger than males and have a brood chamber under their outer carapace where eggs are carried.

Daphnia are an extremely important part of aquatic food chains. They eat primary producers such as algae, yeast, and bacteria. Daphnia are the prey of tadpoles, salamanders, newts, aquatic insects, and many types of small fish. Fluctuations in Daphnia populations can cause algae overgrowth or even a drastic drop in fish populations. Through the food chain, larger animals caught or eaten by humans can be affected by large changes in Daphnia populations

Source: Anne Deken, Missouri

Wednesday, 2 July 2014

Robust and precise: The new inverted AE2000MET for material sciences is ready for you!

The sample always defines the microscope! This rule is especially valid for inverted microscopes, where large and/or heavy samples require more working space, a fixed stage plate and a focusing mechanism through the revolving nosepiece. In biology and medicine, it’s about petri dishes, flasks and well plates, which are treated with transmitted light or fluorescence. In material sciences, the mostly opaque, non-transparent samples will be handled by reflected light methods.

The new inverted material microscope AE2000MET is especially designed for bulky samples in industrial quality inspection and material sciences. The 5-fold nosepiece carries newly developed LM Plan Achromatic objectives with extended working distances, suitable for bright field (BF) and dark field (DF). These lenses perform an extraordinary image quality for QC and research applications.

The 50W halogen illumination with external power supply delivers plenty of resources for BF, DF and simple polarization. A clever sleep mode turns off the illumination in case the user leaves the instrument. When changing from DF to BF, the illumination power is shut down in order to avoid dazzling.

The full integration into Motic’s CCIS© Infinity Optics allows the use of numerous accessories like alternative eyepieces, reticles, but also EC-M objectives with improved resolution power.

For industrial training and QC, the AE2000MET takes advantage of robust mechanics, easy handling and powerful optical performance. Have a look on it now!