Antibody News

Microtubule-associated protein light chain 3 (LC3) is considered one of the definitive markers of autophagy, and its use is widespread in labs throughout the world. Despite its popularity, there are several considerations when employing LC3 antibodies in immunoassays, Western blots in particular.

LC3 is expressed as a propeptide and is subsequently cleaved to form LC3-I.  Initiation of autophagy causes the conversion of LC3-I to LC3-II via the addition of a phosphatidylethanolamine (PE) group to the C terminus.  The PE group increases the rate of band migration in an SDS-PAGE gel, likely due to its hydrophobic nature; this modification commonly manifests as the appearance of a doublet in a Western blot.  The lipophilic character of the PE group also facilitates the insertion of LC3-II into the membranes of...

What are Western Blot Loading Controls?

Western blotting is an essential technique to probe protein expression in complex cell or tissue lysates. To accurately determine protein expression and interpret Western blot results, it is important to use loading controls. A loading control antibody helps determine if samples have been loaded equally across all wells. Additionally, a loading control serves as an internal positive control, showing that reagents are functioning properly and efficient protein transfer to the membrane has occurred during the western blot protocol. When considering a loading control for your experiment, it is important to choose a protein that does not have a similar molecular weight to your target of interest. Additionally, the loading control protein should demonstrate strong, ubiquitous expression. Choosing a loading control whose...

Epitope tagging is a procedure that inserts a short amino acid sequence into a protein within an expression vector via genetic engineering. Antibodies that recognize the tag can then be used to detect the protein when no antibody to the target protein exists or when the target protein shows low immunogenicity.  Such tags can be inserted at the C-terminus, N-terminus or even within the protein itself.  Terminal insertion is preferred as internal tags may alter protein function or become buried within the tertiary structure of the protein. Initially tags were used to facilitate purification (e.g. 6xHis^®, GST), however they are now used in Western blots, IHC, immunoprecipitation and flow cytometry.

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MAP1LC3 (shortened to LC3 in our antibody catalog) is one of four mammalian homologues of autophagy-related protein 8 (Atg8). It has been identified as a light chain subunit of the microtubule-associated proteins MAP1A/MAP1B. A modified form of LC3, LC3-II, has been identified as a marker for the autophagosomal membrane in mammals.

To date, LC3 is the only known reliable autophagosome marker. Three transcript variants (LC3A, B and C) have been identified in mammals, which undergo post-translational modification during autophagy. LC3 immunoblot assays generally reveal two bands: LC3-I, (the cytosolic form,) and LC3-II (the membrane-bound, lipidated form.)

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The loading controls on our antibody database are widely used in gel electrophoresis and Western blotting studies. Products like the GAPDH antibody detect "housekeeping" proteins which are abundantly distributed in cells. This makes them useful for checking the even loading of gel samples, and the even transfer of proteins at the blotting stage. They also serve a purpose in quality control, by verifying reagents are working correctly, and in the standardization of experimental results. All the loading control proteins on our antibody database are highly expressed throughout the eukaryotic cellular system, though some are localized to one particular area (e.g. COX IV is specific to the inner mitochondrial membrane.) Loading controls may be subcellular fractions, or entire proteins such as GAPDH.

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The HIF family are heterodimeric, oxygen-sensitive transcription factors comprising an alpha and beta subunit which are normally dissociated in normoxic conditions. Our antibody catalog contains products targeting all the Hypoxia Inducible Factor isoforms which have been identified in mammalian cells. These include HIF-2 alpha antibody reagents targeting both the entire protein and specific epitopes.

HIF is an alpha/beta heterodimer that is activated by hypoxic conditions, binding hypoxia response elements (HREs) at target gene loci. The first HIF isoform to be discovered was HIF-1, which in 1995 was identified as a transcription factor for the EPO (erythropoietin) gene in renal fibroblasts. Further research showed the alpha subunit to be located in the cytosol, being rapidly degraded in...

Tubulin is a heterodimeric complex composed of alpha and beta subunits. Just like histones, tubulin can undergo post-translational modification, to affect cellular function. Novus Biologicals offers a large database of modified Tubulin antibody products.

Tubulin is the key building block of microtubules, found in practically all eukaryotic cells. The microtubules are essential to structure and mobility, being involved in mitosis, meiosis, flagella movement, organelle mobility, intracellular transport and cytoskeletal function. The detection, isolation and study of microtubular proteins, through alpha and beta Tubulin antibody research, are essential to the understanding of microtubule function.

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The Survivin antibody is widely used in apoptosis studies, and as a cellular marker. Today, biochemists have a wide range of Survivin antibody products to choose from, suitable for use in Western Blot, Chromatin Immunoprecipitation (ChIP), Immunofluorescence and similar assays.

ELISA (Enzyme-linked immunosorbent assay) is a popular tool in Survivin antibody research. In simple terms, ELISA involves binding of an antigen to an enzyme-linked antibody, which must be highly specific. Various formats of this basic technique have been developed, the most powerful of which is the Sandwich ELISA assay. Sandwich ELISA is dependent upon antigens with at least two binding sites, as it uses both a capture and a detection antibody, between which the sample is “sandwiched.” This has several benefits over standard ELISA, including increased sensitivity and the fact samples do not need to be purified prior to analysis...

The Hypoxia Inducible Factors (HIFs) are a family of mammalian transcription factors which are expressed in response to low cellular oxygen concentrations (hypoxia). Three human hypoxia inducible factors have been identified, HIF-1, HIF-2 and HIF-3, each having an alpha and a beta subunit. Our antibody catalog at Novus Biologicals includes a full range of HIF products, including  useful HIF-1 alpha antibody packs containing multiple different samples. The Hypoxia Inducible Factor antibody catalog is widely used in disease research, as hypoxia is a contributing factor in the pathogenesis of many diseases, including kidney disease. Hypoxia is also a common complication following renal allograft, or transplant surgery, resulting in necrosis and...

Hypoxia-Inducible Factor-1 (HIF-1) is a highly conserved heterodimeric transcription factor. Novus' antibody catalogue contains an extensive range of both HIF-1 alpha and HIF-1 beta, useful for hypoxia, angiogenesis, cancer and many other areas of research.

The Hypoxia-inducible factors play an essential role in homeostasis, responding to changes in the available oxygen content of the cell. Specifically, they respond to hypoxic, or low oxygen conditions. There are three main members of the human HIF family, each comprising an alpha and beta subunit, encoded by a separate gene. All these proteins are represented in our antibody catalog, which has a particularly extensive range of top quality HIF-1 alpha antibody products...

The ABC (ATP-binding cassette) transporters are a superfamily of transmembrane proteins which play an essential role in membrane transport in both prokaryotes and eukaryotes. In humans, ABC transporters have been implicated in many conditions. For example, ABCA1 antibody research has shown mutations in the ABCA1 gene can cause Tangier disease, while the ABCB family causes multiple drug resistance. We at Novus Biologicals have a large antibody database of ABC transporters and related proteins, for a variety of species and applications.

ABC transporters use energy harnessed from ATP hydrolysis, to carry out a range of functions, including the translocation of lipids, drugs and metabolic substrates across intracellular and extracellular membranes. However, research has also shown that some proteins do not have a membrane transport...

We at Novus Biologicals have a large catalogue of protein, peptide and antibody products to choose from. To make life easier for researchers, our catalog includes products like the actin antibody pack, which contains two actin antibody vials mapped to the N-termini of human beta and gamma actin.

Antibody packs contain multiple vials of similarly targeted immunoglobulins, which researchers can test to find the best product for their assay. Buying them in kit form saves the tedium of hunting through the catalog to match up likely products (of which there are over 500 for the actin antibody alone). However, the process can be improved even further with the Precipitor^TM Affinity Magnetic Precipitation System.

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