In the short time since part 1 of this series “Coronavirus in Histology” was published, the COVID-19 virus has continued its spread around the globe. Currently, the entire country of Italy is on lock down. The BBC reports (1) that the Italian government has implemented emergency measures related to the coronavirus outbreak, which include a ban on public gatherings and a travel ban for all residents of the entire country. There are other ramifications occurring around the globe as well.
An important and timely article was published online in the Journal of Histotechnology 01 March 2020. The article “Coronavirus disinfection in histopathology” by Anthony F Henwood (1) was referenced by Gayle Callis on the NSH Open Forum and has been granted open access. Everyone is urged to read the entire article. Herein is a review to provide the essential findings of the article.
The DNA of a nucleus directs the actions of the cell by instructing it to manufacture specific proteins. This “instruction” is sent from the nucleus into the cytoplasm by “messenger RNA” (mRNA).
Rankin Biomedical donated a variety of laboratory supplies to Lake Fenton High School. From syringes to block heaters and stainless steel instruments, the supplies are being put to great use in Biology, Chemistry and Physics classes!
In previous installments of the IHC Educational Series, we discussed the specifics of the basic procedures found in the IHC laboratory: immunofluorescence, immunohistochemistry and in situ hybridization. Even though these are different procedures, they all require the following support procedures.
The term “in situ” means “in the original place”, while “hybridization” refers to a hybrid composed of one strand of DNA with a complementary strand of nucleotides – which is referred to as a probe.
Rankin attended the 2019 Michigan Microscopy and Microanalysis Society (MMMS) Meeting held at Kellogg Hotel and Conference Center in East Lansing, MI on October 31, 2019.
In the previous units of this series, the immunohistochemical (IHC) methods of immunofluorescence and immunoperoxidase were described and discussed. These methods use antibodies to localize cellular proteins in tissue sections, which can then be visualized in either a dark field fluorescence microscope or routine bright field microscope. It is important to understand antibody structure and function in order to fully appreciate these immunohistochemical (IHC) techniques.
In the previous segment, immunofluorescence methods were discussed. These methods use antibodies labelled with fluorescein to directly localize cellular proteins in tissue sections, which can then be visualized in a dark field fluorescence microscope. Despite the advantages of this method, science is always in search of newer methods to gain more knowledge. Thus in 1970 Sternberger et al (1970) reported an improvement of Graham’s method (1965) using horse radish peroxidase enzyme (HRP) labelled antibodies to localize antigens and visualize them in the routine light microscope – bringing the method “to light” as one might describe. Now researchers and pathologists could see protein localization within the histology of formalin fixed paraffin embedded tissues viewed using a routine bright field microscope. This provided vast improvements over the immunofluorescence method.
Before we discuss immunofluorescence, we need to know what fluorescence is. There are certain substances, composed of molecules that will emit light when irradiated by a short wavelength, such as X-rays or ultraviolet (UV) light.