Monday, 30 March 2015

Distinct differentiation of urine sediments requires Phase Contrast as a method of choice

Besides the identification of urinary passage infections a qualified investigation of urine sediments always has to reveal their renal or post-renal origin. As a consequence, bacteria, cylinder and erythrocytes have to be recognized clearly.

The microscopic examination of urine sediments deals with unstained, native samples; single colorless components can hardly be recognized in transmitted bright field and thus are easily overlooked.

Only an adequate contrast method will ensure the positive detection of cells and other low-contrast structures in urine sediments.

The necessary image quality can easily be achieved by using the optional Phase contrast on a transmitted light microscope. A quick switch between bright field and Phase contrast is possible and facilitate both illumination methods on one instrument.

Colored crystals and cell aggregations are treated with bright field, while Phase contrast allows a detailed identification of morphologic anomalies like dysmorphic erythrocytes and hyaline matrices (cylinder).

Some examples:

Picture 1 and 2

Phase contrast allows the distinct detection of the cylindrical structure. In bright field the Tamm-Horsfall protein is quite transparent and can easily be overlooked. In case cell structures are located within a hyaline matrix, the renal origin of these cells is obvious. The morphology of erythrocytes (eumorphic or dysmorphic) gives evidence to renal or post-renal bleeding.

Picture 1

Picture 2

Picture 3 and 4

The abundance of bacteria

Friday, 27 March 2015

Dodder, a spiraling parasite

Dodder (Cuscuta and Grammica), is a twining yellow or orange plant sometimes tinged with purple or red. Occasionally it is almost white. Dodder can be identified by its thin stems appearing leafless, with the leaves reduced to minute scales.

Dodder is classified as a member of the Morning-Glory Family (Convolvulaceae) in older references, and as a member of the Dodder Family (Cuscutaceae) in the more recent publications. Dodder parasitizes various kinds of

Wednesday, 25 March 2015

There is always some sun shining

Above we can see an aciculate aragonite that comes from Toledo. Its particular acicular form is determined by the ordering of its atoms, which tend to grow faster in the radial direction than in the others. This provides us needle-like structures all coming from a crystal nucleus.

Interestingly, its chemical formula is CaCO3, the same one as the calcite. Yet they are considered polymorphic

Monday, 16 March 2015

Antony van Leeuwenhoek was the first to discover…

Eimeria stiedae is a species of Eimeria (protozoal parasites) that causes hepatic coccidiosis in rabbits. It was observed for the first time by Antoni van Leeuwenhoek

Monday, 2 March 2015

Parfocality adjustment for upright microscopes

Parfocalty is a property of the optical components that allows the microscope to stay in focus when changing between lenses of different magnification.

This means that when the objectives of a microscope are changed from higher to lower magnification or vice versa, the sample you are viewing stays in focus.

This is important especially when taking photographs or making videos using a microscope and a camera. If the parfocality is not adjusted, the camera will not be focusing correctly, even if the image seen through the eyepieces is in focus.

To ensure the correct parfocality adjustment of your microscope, just follow these easy steps:

1. Adjust the interpupillary distance so that both the right and left field of view become one.

2. Set the diopter adjustment on both eyepieces (or on eyepieces tubes) on the “0” position.

3. Select the lowest magnification objective and