Histology Blogs and Articles to Help Anatomical Pathology Labs

#5: In Situ Hybridization

In situ hybridization

In the previous segments of the IHC Educational Series, immunofluorescence and immunoperoxidase methods were discussed.  In both of these methods, antibodies are used to bind to and localize protein antigens in tissue sections.  Additionally, the differences between the use of polyclonal and monoclonal antibodies had been described. Another immunohistochemical method is “in situ hybridization”. The …

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2019 Michigan Microscopy and Microanalysis Society Meeting

2019 Michigan Microscopy and Microanalysis Society Meeting

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. Rankin’s tie-in to the MMMS meeting was by invitation from Victoria Kimler, PhD, CMA, the lab manager of the Ocular Structure and Imaging Lab at Oakland University’s Eye Research …

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#4: Antibodies

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 …

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#3: Immunoperoxidase

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 …

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#2 Immunofluorescence

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.  The emitted light is of a longer wavelength which has a lower energy.  Two substances that are used in microscopy …

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#1 Introduction to Immunohistochemistry

Introduction to Immunohistochemistry

Anthony van Leeuwenhoek is credited with being the first person to use a microscope to view tiny “animacules” in 1674. At approximately the same time, Robert Hooke used a similar microscope to view thin slices of cork. The structures that he observed resembled the tiny cells that monks lived in at the local monastery, so …

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#7 Tissue Processing Artefacts

Theory, Chemistry And Physics of Tissue Artefacts

The most noticeable tissue processing artefacts are the wrinkles and tears in the tissue sections which are evident even at low power (Figure 1).  Incomplete fixation would not cause such artefacts, as the cellular histology is acceptable (i.e. nuclear and cytoplasmic staining is within quality control limits).  Improper embedding would also not be the cause …

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#6 Understanding Tissue Processor Procedures

Understanding Tissue Processor Procedures

Tissue Processing Standard tissue processing may be carried out on any number of open and closed tissue processors, although closed processors are preferred due to safety concerns, both for the tissues and laboratory personnel.  Closed system processors are “smart’ enough to prevent tissues from drying out in the event of a power failure, and the …

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#5 Troubleshooting in the Histology Laboratory

Chemistry of Fixation, Processing and Staining in the Histology Laboratory

The first four blogs of the troubleshooting series focused on being proactive with regard to the prevention of sub-optimal events in the histology laboratory.  Unfortunately, we are not able to predict every single potential issue that may cause a sub-optimal event in the laboratory.  As a result, another strategy is required.  This next series of …

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#4 Alternative Methods for Preparing and Embedding Specimens

Alternative Methods for Preparing & Embedding Specimens

Some specimens may be very tiny; on the order of less than 0.1 cm. Some preparation methods employ the use of mesh cassettes, “tea bag” biopsy pouches, sponges, wrapping paper, etc. to contain the specimen and prevent it from escaping the tissue processing cassette. A disadvantage of the above methods is that upon embedding, the …

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