The hemocytometer (or haemocytometer or counting chamber) is a specimen slide which is used to determine the concentration of cells in a liquid sample. It is frequently used to determine the concentration of blood cells (hence the name “hemo-”) but also the concentration of sperm cells in a sample.

The resolution that a microscope is capable of achieving is probably the single most important factor that determines the quality of a microscopic image. Without a sufficiently high resolution, magnification is not possible without loss of quality. Read the following introductory post: . There are a variety of different factors that determine the achievable resolution. [...]

The thickness of the cover glass can have a significant impact on the resolution. The effect is highest with high-numeric aperture aperture (high magnification) objectives, and barely noticeable when using objectives of a low numeric aperture. Types of cover glasses Cover glasses come in all sorts of different sizes. I already wrote a post about [...]

And yet again it’s time to answer some reader questions What are the things that all types of microscopes have in common? Microscopes can be very different (see . I therefore limit the answer to light microscopes. Things that optical microscopes have in common include: Objectives, Oculars/eyepieces, stage (carries specimens), light source, focusing system. Does [...]

This time I’d like to talk about a topic which is only indirectly related to microscopy: macro imaging. Taking high-quality macro images can be quite a challenge and can involve quite a bit of trial and error until one has found the ideal conditions. The pictures of the rose have been taken with a Sigma [...]

Volvox is a fresh water green algae and a member of the Chlorophyta. The picture shows a spherical volvox colony, each ball can contain hundreds, if not thousands of individual cells. The picture shows six daughter colonies inside the main colony. The main colony disintegrates and the daughter colonies are then released. Volvox is a [...]

This is one of the first tries taking pictures with my new Sigma objective, and I have to admit that I’m very satisfied with the lens. The lens does not include image stabilization, a steady tripod is therefore a must. Contrast was slightly enhanced to make the background (my computer screen!) completely black. Mirror lock-up [...]

The mounting medium can have a significant effect both on the image quality and on the specimen itself. I tried a little experiment by observing pollen from a plant (in this case the buttercup, Ranunculus), mounted in five different ways: Air-mounted, with no cover glass Air-mounted, with a cover glass Mounted in water (temporary mount) [...]

In this post I’d like to address some of the search queries that people typed to find this web site. Naturally people typed many, many more search queries, most of the queries are made of 1 or 2 words. I selected the longer ones for this post. Q: What is the principal advantage of an [...]

Spring time is pollen time! Here are two images of Ranunculus repens (the Creeping Buttercup or Creeping Crowfoot) pollen, the top one in dark field, the bottom one in bright field. This plant is poisonous and can cause skin irritation. The name “Crowfoot” comes from the shape of the leaves, which resemble the claws of [...]