Fixation on Histology

Using Immunohistochemistry Double-Labeling to Detect SARS-Cov-2 Infection

IHCDoubleStaining1Immunohistochemistry (IHC) is a useful tool in clinical diagnosis and used to localize specific antigens in tissue sections with labeled antibodies based on antigen-antibody interactions. Immunohistochemically double labeling is a common method used to evaluate two distinct antigens in a single tissue and are easily performed by using automatic system, such as Leica BOND IHC/ISH auto-stainer.

To report a case of SARS-CoV-2 infection during pregnancy, immunohistochemically double labeling on placenta sections from an infected newborn provides researchers some insights. The
in situ information of virus-infected cells as well as the intervillous inflammatory infiltration in the placenta are detectable (see image above).

IHCDoubleStaining2We use human skeletal muscle biopsy to validate the immunohistochemical double labeling pressure. Two mouse monoclonal antibodies, the same antigen retrieval condition (Leica BOND ER1 pH 6.0), and exact chromogenic detection kits were used for this purpose.

We show that anti-slow muscle myosin (Type 1 fiber, MAB1628, EMD Millipore, detected by BOND Polymer detection kit DAB) and anti-skeletal fast myosin (Type 2 fiber, M4276, Sigma-Aldrich, detected by BOND Polymer Refine Red Kit) properly labeled their targets as it supposed to be (see right image).
IHCDoubleStaining3In summary, our double labeling immunohistochemistry procedure on a Leica BOND IHC/ISH autostainer system was working properly. Using that procedure, we reported a placenta pathology that SARS-CoV-2 infection remained in mother portion of placenta without transmission to the fetus part.

Written By Dr.Minhui Ma, MS, MD