Wednesday, 27 July 2016

Tiny packages that contain all information necessary for life

Chromosomes are the packages that hold DNA. They play an essential role in genetics - they are the parcels of genetic material that are passed down from parents to children and together contain the full set of inherited instructions that an embryo receives.

Monday, 18 July 2016

The microscope objective - the key issue for best image performance

Different samples require different microscopes. This rule refers to the fact that an opaque, bulky sample with a reflective surface needs another treatment than a transparent, unstained smear from the cavitas oris. The microscope stand offers the necessary space for a correct positioning of the sample and all options for the appropriate illumination method.

 The microscope objective is an even more specific item. Here we talk about the required resolution power (= numerical aperture), but also about cover glass correction, immersion method and working distance.

1. The standard upright microscope for transmitted light is constructed for glass slides with a 0.17mm cover slip. This restriction is indicated on the objective sleeve:

Cover slip thickness indicated on Motic's Plan UC Fluor objectives

The cover slip has to be placed on top of the sample. A slight pressing of a dissecting needle will help to avoid too much embedding medium (water, etc.) between sample and cover slip. The embedding medium in this case works as an

Thursday, 14 July 2016

Tar spot (Rhytisma acerinum)

The microscopic image shows an infected leaf with sclerotia. A consequence of monoculture.

Just like buildup of mold on pine needles and on the leaves of the willow, an ascomycete (Rhytisma) is the cause of tar spot. From late summer to autumn, round black mold deposits are growing on the leaves of several species of maple, which overwinter on the ground after the falling of the leaves. In spring distribution

Tuesday, 5 July 2016

When you still need a microscope to see Giant structures

Giant chromosomes can be observed in the salivary glands of certain two winged flies (Diptera) and were first observed by Balbiani in 1881 [1]. These chromosomes are oversized and develop from standard chromosomes when specialized cells