Blogs for April 2017

Why do counterstaining in ICC/IF and how?

Friday, April 28, 2017 - 10:26

Why: To identify a specific organelle or another cellular structure and to mark individual cells, it is necessary to counterstain them in immunocytochemistry/immunofluorescence (ICC/IF) assays.

How: Counterstaining is often performed with dyes or antibodies specific to the organelle or cellular structure of interest. For example, the nuclear counterstaining is carried out by using DNA helix intercalating dyes such as DAPI and Hoechst which can penetrate the cells and nuclei without permeabilization. Similarly, fluorescently-labeled phalloidin is used for counterstaining the cytoskeletal actin filaments and fluorescently-tagged wheat germ agglutinin (WGA) is employed for counterstaining the plasma membranes.

Important Considerations: When choosing counterstaining options in...

The role of MHC Class II RT1B and immune response post brain injury

Tuesday, April 25, 2017 - 09:39

The major histocompatibility complex (MHC) is responsible for binding peptide fragments arising from pathogens in order to display them on the cell surface for recognition from immune cells.  Once recognized, the foreign pathogen is typically evaded. The MHC complex is broken into two categories, MHC Class I proteins and MHC Class II proteins.  MHC complex I and II proteins are all very different and contain specific molecules to bind different peptides – in fact, they have been described as the most polymorphic genes there are. The MHC Class II RT1B antibody can be used to bind the monomorphic determinant of the rat I-A antigen, which is found on B-lymphocytes, dendritic cells and some macrophages. Often times, a neuroinflammatory response develops after brain injury and remains for weeks post injury.  Using a MHC Class II RT1B antibody is a useful way to understand...

Novus Marches for Science!

Friday, April 21, 2017 - 10:15

Novus employees will be participating in the March for Science alongside a global network of scientists to support the education and public importance of this topic for all.

We believe in the integrity of science and all that it holds for the future. Everyone is affected by it, and we believe in sharing this information with the public, outside of labs and journals.

Join us on April 22, 2017 at the March in D.C. or at your local satellite event. #BioTechneMarches

We will be marching in our Bio-Techne communities:

  • Minneapolis-St. Paul, MN
  • Denver, CO
  • San Jose, CA
  • Washington, DC
  • Boston, MA
  • Bistol, UK

And more!

Follow our employees on social media with #BioTechneMarches throughout the weekend for scenes from around the world.

The role of c-Fos in the regulation of the JC virus gene transcription

Thursday, April 20, 2017 - 11:10

c-Fos is a member of the AP-1 transcription factor family under the Fos protein family umbrella, alongside Fra-1, Fra-2 and Fos-B.  Also in the AP-1 transcription family are the Jun proteins, c-Jun, Jun-B and Jun-D.  Each member of the AP-1 transcription family is a phosphonuclear protein composed of a carboxy-terminal leucine zipper domain, a basic domain and an amino terminal transactivation domain. Together the Fos and Jun families compose a dimeric complex that binds to response elements on DNA in order to regulate gene expression, cell proliferation, cell differentiation, tumorigenesis and more.  Their induction can be catalyzed by a number of signals, including cytokines and growth factors, stress and viral infection. ...

The advantages and applications of using tissue microarrays

Monday, April 17, 2017 - 15:04

A tissue microarray is a fairly recent high-throughput application that allows researchers to test hundreds of tissue samples with antibodies of their choice at once.  Essentially, a tissue microarray is a paraffin block that is produced by a composition of tissue cores from paraffin donor blocks within defined coordinates to account for a variety of tissue types. Due to the success of the traditional IHC experimental method in advancing clinical research and drug discovery, the introduction of high-throughput IHC is pivotal to understanding the transformation of tissues from healthy to malignant.  This article will go deeper into the pros and cons of tissue microarray, as well as introduce tissue array sets available at Novus Biologicals and real world applications. 

tissue comparsion slide


An overview of permeabilization in immunocytochemistry (ICC)

Thursday, April 13, 2017 - 09:12

Immunocytochemistry (ICC) can be a very effective method for visualizing the localization and behavior of intracellular proteins, however the protocol for each ICC experiment should be optimized specifically to the cell being examined.  Permeabilization, or the puncturing of the cell membrane, is an extremely important step in detecting intracellular antigens with a primary antibody because it allows entry through the cell membrane. Permeabilization is introduced after cells have been prepared with a fixative agent to initiate protein cross-linking, such as formaldehyde or ethanol. However, determining the amount of exposure to a permeabilization agent is crucial, seeing as a hard tissue organ may require a longer incubation over a soft tissue organ and treating your sample incorrectly will lead to unreliable results. 


Pathway Highlight: Which caspase substrates contribute to the morphological features associated with apoptosis?

Tuesday, April 11, 2017 - 09:20

Apoptosis, or programmed cell death, is controlled by a caspase signal cascade that activates downstream signals to induce the morphological changes used to differentiate apoptosis from other forms of cell death.  Novus Biologicals offers a variety of antibodies and tools to detect the different morphological indicators of cell death. 

Nuclear Fragmentation

Nuclear condensation starts at the nuclear membrane, hallmarked by the formation of a ring-like structure.  Further into apoptosis, the nucleus full fragments in a process known as “karyorrhexis”.  Primary antibody markers that bind and recognize DNA such as ICAD (inhibitor of caspase-activated DNAase) and Lamin B can be used to visualize nuclei.  Furthermore, TUNEL, or terminal deoxynucleotidyl transferase (TdT)-mediated dUTP in situ nick end labeling, is a popular method of apoptotic cell...

Key Targets in Apoptosis, Necroptosis, and Autophagy

Sunday, April 2, 2017 - 14:16

Cell death/recycling pathways such as apoptosis, necroptosis, and autophagy are an integral part of the growth, development, homeostasis as well as the pathophysiology in the life of living organisms. These signaling pathways are highly regulated and some of their key regulatory targets are discussed below.


Apoptosis, programmed cell death, is primarily characterized by the activation of caspases which further regulate the mass cleavage of proteins and DNA. Some of major the proteins responsible for various apoptotic events are:

Initiator Caspases
(-2, -8, -9, -10)

In apoptosis, initiator caspases are involved in the upstream events of death receptor (extrinsic)- or mitochondrion-dependent (intrinsic) signaling pathways. They...

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