Multiplex ELISA

Renal injury biomarkers

25/07/2016 By Philippe Fixe, PhD Leave a Comment

Renal injury can sometimes be induced by drugs. Some examples of renal damage-inducing drugs include some widespread treatments, such as ß-Lactam antibiotics, bisphosphonates, non-steroidal anti-inflammatory drugs, diuretics, aminoglycoside antibiotics, antineoplastic agents and radiocontrast agents.

Since 2008, both the FDA and the EMEA indicated that additional tests may be necessary to assess new drug safety and prevent from renal toxicity. Though these recommendations are voluntary, many pharmaceutical companies have started gathering data on nephrotoxicity biomarkers. [Read more…]

Global cytokine profiles and cancer drug resistance

10/05/2016 By Philippe Fixe, PhD Leave a Comment

The role of the interactions between tumor cells and their microenvironment (TME) is now well-established in various stages of cancer development. Cytokines, produced by both the cancer and the immune cells, actively contribute to these critical connections (see the previous posts related to the crosstalk between cancer and immune cells in relation to tumor escape,� immunoediting and� immunosurveillance).

In a recent review published in BBA, RayBiotech‘s team highlights the “cytokine signatures and dynamics” seen during cancer development. They also demonstrate the necessity of designing relevant multiplex immunoassays for the profiling and the quantification of cytokines in biomarker and anti-cancer drug discovery programs.

Source:
Valerie Sloane Jones, Ren-Yu Huang, Li-Pai Chen, Zhe-Sheng Chen, Liwu Fu, Ruo-Pan Huang “Cytokines in cancer drug resistance: Cues to new therapeutic strategies” (2016) Biochimica et Biophysica Acta, Volume 1865, Issue 2, 255–265. DOI:10.1016/j.bbcan.2016.03.005.

Download the publication written by RayBiotech, the leader in planar Antibody Arrays.

Find out more about RayBiotech’s Antibody arrays and Protein Multiplex Quantification Lab services by tebu-bio.

How sample preparation can affect your biomarker studies (II)

11/12/2015 By Ana Arraztio Leave a Comment

In a previous post, we looked at the importance of sample preparation methods depending on the biomarker being studied (e.g. MMPs, cytokines). Today, let’s focus on cell / tissue lysates. [Read more…]

Crosstalk between cancer and immune cells: tumor escape

02/11/2015 By Ana Arraztio Leave a Comment

A crosstalk between cancer and immune cells is established during cancers. The immune system is able to fight against tumour cells (see my previous post “Immunosurveillance: Crosstalk between cancer and immune cells”). But what happens when immunosurveillance fails?

This is the subject of this new post. A selection of validated immunoassays allowing you to monitor cytokines and signal transduction biomarkers involved in these “loops” is also introduced.

[Read more…]

Secretome profiling – now quantitative!

28/09/2015 By Ana Arraztio Leave a Comment

For secretome biomarker profiling, several solutions, including arrays allowing to screen up to 1,000 factors, have been available for some time now. These profiling solutions, however, were semi-quantitative so far. Quantitative solutions were available for “only” up to 400 factors.

Recently, a new array allowing to quantify 640 human secretome factors has been released. This array is available as a product (to use in your lab), or you can have the array performed for you (tebu-bio’s laboratories, located near Paris). [Read more…]

STAT3 signaling effects on IL-15 derived dendritic cells

22/09/2015 By Ana Arraztio Leave a Comment

The role of STAT3 signaling in the activity of dendritic cells (DC) has been recently revealed in a publication by Okada et al.

ELISA array analysis of cytokine expression profiles of LPS/TNFα-treated IL-4 and IL-15 DCs (table from publication).

Dendritic cells (DCs) are important innate and adaptive immune effectors, and have a key role in antigen presentation and T-cell activation. Different lineages of DCs can be developed from hematopoietic progenitors following cytokine signaling (e.g. IL-15, IL-4), and the various lineages of DCs display distinct morphology, phenotype and functions. [Read more…]

How sample preparation can affect your biomarker studies (I)

10/08/2015 By Ana Arraztio Leave a Comment

In previous posts, we have discussed about whether samples should be pooled, how much (and if) they should be diluted, and how biologicals can affect the final results…and the biomarkers that you find.

Today, we will discuss some cases where preparation of samples per se can affect the final outcome of your experiment. And for some markers, in some dramatic way. [Read more…]

Normalisation assays in biomarker studies – all’s well that starts well

20/07/2015 By Ana Arraztio Leave a Comment

The normalisation of quantitative assay data is critical when interpreting effective biological system status. With cells grown in culture and lysed, a simple total protein determination such as the Bradford assay (developed by Marion Bradford at the University of Georgia in 1976) can be enough by giving an estimate of the total cellular proteins. However, this type of measurement, along with Lowry and other dye binding assays, can be prone to errors due to various factors such as detergent, chelators… Standardization also involves the use of a protein of interest. Here again, the protein used is crucial for the accuracy of the overall assay.

[Read more…]

Discovery of new biomarkers… 3 tips regarding controls

08/07/2015 By Ana Arraztio Leave a Comment

One of the recurrent questions that we get at the Biomarkers team at tebu-bio is on what controls should be included in a given experiment. Either if the experiment is done by researchers in their lab, or if we collect their samples and perform the analysis in our lab, a good design starts by using the most convenient controls.

One of the controls is related to the study itself. In this sense, definition of what a control population is, and how we want to study it vs. a cohort of patients has been discussed elsewhere in a proteomics post. Today, we will put our spotlight on the “technical” controls, i.e. those related to the technique itself. [Read more…]

Biomarker profiling: Diluting samples case studies (II)

01/04/2015 By Ana Arraztio Leave a Comment

Back to dilution of samples. After our post on whether samples should be diluted or not, let’s discuss today about how much they should be diluted.

Case # 1 – ELISA or simplex assays

Most ELISA manufacturers indicate the dilution range for different types of samples (serum, plasma, cell culture supernatants, etc.) to be used in their products. However, the dilution range can sometimes be from 1:2 to 1:2,000. How to choose the right dilution factor?

The honest answer is: nobody knows. That is, nobody knows what is the right dilution factor in your specific research project, for your specific biomarker. [Read more…]