Antibody News

Hypoxia inhibiting factors protect the cell from death. Autophagy proteins do the opposite. However, hypoxia-induced autophagy has been shown to have a role in cell survival by targeting only the organelles which are oxygen-demanding i.e. mitochondria. Although useful, the mechanism has been implicated in the development of tumours, therefore antibodies against the relevant proteins feature highly in the cancer research pages of our antibody catalogue.

Cell survival under hypoxic conditions is controlled by the HIF (hypoxia-inducible factor) family, complexes of transcriptional proteins which are normally dormant, but are activated by the reduction of intracellular oxygen tension. HIF proteins control a number of gene pathways which then work to restore homeostasis. Several of these proteins have shown to be active in forming cancerous tumours.

Studies using antibodies specific against cell cycle regulatory proteins have opened up many new avenues of cancer research. The mammalian cell undergoes 4 distinct phases during mitosis. Initiation is controlled by assembly and activation of the CDK proteins (Cyclin Dependent Kinases.) There activation is governed by phosphorylase modifications and the regulatory kinase subunit cyclins. Cyclins comprise two groups: G1 and G2, or mitotic cyclins. The G1 group regulates G1 to S-phase progression of mitosis, while the G2 cyclins control G2 to M progression.

The cyclins bind to CDK, leading to phosphorylation and inhibition of pRb, a tumour suppressor protein which controls progression from the G1 to S phase. Studies show this is partly done by the inhibition of the E2F transcription factors, which are known to encourage cell growth.

The proteins regulating the cell cycle are of interest in oncology studies, as both D-type cyclins...

Research into checkpoint signalling (CPS) forms a major part of IHC research. CPS regulates DNA repair mechanisms, apoptosis and cell cycle progression. Antibody research into checkpoint proteins has also shown they play an essential role in tumour development. ATM and ATR are two important checkpoint mediators which are well reported in cancer studies.

Cellular checkpoints are signal transduction pathways which interact with many other mechanisms, such as that governing growth factor availability. We at Novus Biologicals have a large number of CPS immunoglobulins on our antibody database.

The S-phase checkpoint is involved with DNA repair and cell-cycle progression. It is known to react to DNA damage by reducing the rate of synthesis. Although it is still the least understood of the cellular checkpoints, recent studies on infrared-induced S-phase checkpoint activation have thrown valuable...

For those who are new to working in this area of work, it may prove useful to outline a few tips on choosing antibodies.

Immunoglobulins are purchased as primary or secondary, and mono or polyclonal proteins. Primary antibodies bind directly to the antigen, and can be conjugated (labelled) with an enzyme or fluorescent dye, to produce a visible signal when the appropriate substrate is added. This allows direct detection of the antigen.

Alternatively, the primary can be used unconjugated, and probing done with a secondary antibody (conjugated or unconjugated) that binds the primary.

Secondary antibodies have several advantages over primary (10) immunoglobulins. Firstly, it makes immunoassays less expensive, as unconjugated 10 immunoglobulins can be bought in bulk and used as stock reagents for different lab processes. Secondly, you can label...

DNA repair processes allow cells to identify and correct lesions in the DNA helix. It is normal for these lesions to happen. Environmental processes such as exposure to UV light and chemicals, as well as day-to-day metabolic changes, can cause hundreds of thousands in a day.

Some agents can damage the DNA’s ability to encode cell proteins, or cause mutations in the genome which affects cell survival following mitosis. These mutations take many forms, of which double-strand breaks are the most serious. The type of damage, and its cause, determines what DNA repair mechanism will be involved. For this reason, the DNA repair section of an antibody catalogue can have a number of sub-sections; among them are mismatch repair, NER and non- homologous end-joining (NHEJ) antibodies.

NHEJ is used to repair double-strand breaks, and is the dominant DSB repair mechanism in many mammals. The ends are...

We have seen that antibody research can deliver progress in areas where other methods have not enjoyed such success.

Caspase 3 is primarily known as an effector molecule in apoptosis, the process of programmed cell death. However, a study by Jeyasuria et al (Biol. Reprod. 2009, 80(5) pp. 928-934) has found that caspase 3 may have a role in preventing excessive uterine contractions before pregnancy reaches term. This is essential to preventing premature labour. The authors used immunological techniques with a group of antibodies to demonstrate this phenomenon. Smooth muscle γ-actin is a protein found only in smooth muscle. Thus, antibody to smooth muscle γ-actin (ACTG2) from Novus Biologicals was chosen to identify caspase 3 action in the smooth muscle of the uterus.

On the basis of their results, the authors concluded that the elevated activity of caspase 3 seen in the pregnant mouse...

Not everyone knows how antibodies influence animal life, so this article is, in part, a very brief introduction. Apoptosis is triggered by a variety of signals and takes place by one of several mechanisms. These involve cell surface receptors, cytokines, tumour necrosis factors, proteins such as Bcl-2, Bax and Apaf-1, the caspase cascade, and apoptosis-inducing factors.

Specific antibodies can assist in pinpointing exactly which factors and signals are involved in any particular situation.
Apoptosis is vital in the breakdown of early embryonic structures, so as to permit development and maturation. Without apoptosis, the caterpillar cannot metamorphose into the butterfly, the tadpole cannot lose its tail and neural synapses cannot form.
The detachment of the uterine endometrium at the start of menstruation involves apoptosis. Lymphocytes proliferating in response to an antigenic stimulus undergo apoptosis when this immune response is no longer...

Researchers requiring antibody products can have some difficulty in obtaining precisely what they need. However, recent developments may make this dilemma less of an issue than it has proven in the past.

The Novus Biologicals antibody catalog contains close to 105,000 products, with new products being introduced constantly. Researchers who are too hard-pressed to search the catalog can call on the Novus Antibody Concierge. Scientists are encouraged to submit information about their specific needs. The Antibody Concierge service will respond in two business days with details of relevant products. Moreover, if the antibodies needed are not available through Novus Biologicals, information on alternative sources will be supplied.

In addition, Novus Biologicals invites collaboration with investigators via the Novus Antibody Grant Program. Researchers who...

Treating cancer is a major health priority in western society. Coupled with attempts to alter unhealthy behaviour, it is hoped that better cancer treatment can reduce premature deaths.

Anti-APE1 mouse monoclonal antibodies from Novus Biologicals were antibodies used to investigate drug resistance in non-small cell lung carcinoma (Wang et al., Lung Cancer 2009, 65(3), pp. 298-304). Tumour drug resistance results in less successful chemotherapy.

Apurinic/apyrimidinic endonuclease (APE1) has a key role in the repair of DNA damage. By protecting cells from the genotoxic and cytotoxic effects of oxidising agents, APE1 counters the development of a number of pathologies.

Conversely, in the case of tumour cells, the protective effects of APE1 will have negative consequences if they result in the tumour having an increased capacity to resist anti-cancer treatment.

Extra-bright antibodies increase the specificity and sensitivity of any fluorescence-based procedure. They are stable over a wide pH range and are also highly ‘photo stable.’

Novus Biologicals now offer more than 1,150 antibodies conjugated to DyLight® fluorescent dyes.

As fluorescent imaging technology advances, there is a growing drive to achieve increasingly quantitative measurement of fluorescent signals.

Ultimately, this would permit determination of the absolute quantity of a target molecule within a cell or compartment using a fluorescent antibody technique.

A major obstacle to such a technological breakthrough is the fact that the fluorescent intensity of some dyes can be significantly affected by various cellular environmental factors. Cellular organelles show a wide variation in pH, ranging from as...