We describe a novel method of characterizing the longitudinal chromatic aberration of microscope objectives by recording a series of axial responses as a function of wavelength as a plane reflector is scanned through the focal region of a confocal microscope. Measurements are presented for a variety of objectives with differing degrees of correction. The use of the chromatic focal shift to meas...

Introduction In the current world of nanotechnology, fast and reliable measurement of nanoscale features is extremely useful. It is further advantageous if the analytical tools used are cost-effective and have high throughput, such as optics-based tools. In conventional optical microscopy, it is usually deemed necessary to acquire images at the “best-focus” position for meaningful analysis. How...

The aim of this project was to produce guidance for a rationalised virological electron microscopy specimen testing policy for PHLS North West, to facilitate centralisation of a groupwide diagnostic electron microscopy service on a single site. Careful specimen selection to limit numbers and the groupwide use of commercially available enzyme immunoassays has allowed PHLS North West to reduce th...

Vaccinia virus subjected to various repeated treatments and then negatively stained with potassium phosphotungstate was examined with the electron microscope. To obtain reproducible results it was necessary to standardize the preparation procedure. The standarized method now recommended is that the virus should be mixed with stain before being placed on the electron microscope grids and the gri...

Phase imaging provides intensity contrast to visualize transparent samples such as found in biology without any staining. Among them, digital holographic microscopy (DHM) is a well-known quantitative phase method. Lensfree implementations of DHMs offer the added advantage to provide large field of views (several mm2 compared to several hundred μm2) and more compact setups that traditional DHM w...

Advances in technology made the migration of pathological diagnosis to digital slides possible. As the need for objectivity and automation emerged, new computer software algorithms were proposed. Computer algorithms demand accurate color and intensity values in order to provide reliable results. The tissue samples undergo several processing steps from histological preparation to digitalization,...

We report here a new staining procedure which uses both the enzymatic dehydrogenation of 2-(p-iodophenyl)-3-p-(nitrophenyl)-5 phenyltetrazolium chloride to a pink intracellular formazan and the DNA-specific fluorochrome 4',6'-diamidino-2-phenylindole. Application of this staining procedure to cells concentrated on filters and then transferred to microscope slides by the filter-transfer-freeze t...

In the present study, we have determined the growth and development pattern of rostellar hooklets of Taenia solium cysticerci (Zhengzhou and Harbin strains) in three pigs (1 SEM and 2 L-SEM strains) 89-196 days post experimental infection. A total of 3,675 cysticerci were collected from 3 pigs, 3,007 (82%) of 3,675 cysticerci were evaginated by enzyme method. 439 (15%) evaginated cysticerci wer...