Archive
The Assessment of Phototoxicity Using the 3T3 Neutral Red Uptake (NRU) Phototoxicity Assay and a Modified Photo-Direct Peptide Reactivity Assay (DPRA)
March 28, 2018Alternative methods, including the validated 3T3 Neutral Red Uptake (NRU) Phototoxicity assay (OECD TG 432) may be used as a pre-clinical test to address phototoxicity. Currently, there are no validated alternative test methods to identify photoallergens; however, there are several validated alternative test methods to address skin sensitization, including the Direct Peptide Reactivity Assay (DPRA) (OECD 442C). To address photoallergy, we utilized the 3T3 Phototoxicity assay in combination with a modified photo-DPRA assay to determine if these assays were able...
Video: Bovine Corneal Opacity & Permeability Test – Spanish
October 16, 2017This 13- minute training video demonstrates how to perform the BCOP assay according to the Test Guidelines set forth for the assay by the Organization for Economic Co-operation and Development (OECD TG 437). The video focuses on steps that are critical to the success of the assay such as handling of the isolated cornea and removal of the test material from the cornea at the conclusion of the exposure time. ...
Quality Considerations: Redefining Test Systems from Animals to Tissues and Beyond
August 28, 2017The use of non-whole animal test methods transforms the way regulatory requirements are applied in preclinical testing. Recent global regulatory initiatives emphasize the importance of transitioning to human relevant assays and test systems that do not use animals. When these methods are moved from research into the regulated arena, GLP principles must be followed. The GLPs were originally written in the 1970s, when the vast majority of regulated research was performed using animals as the test system. Current innovative, alternative...
Webinar: How GLPs Enhance the Quality of Regulated and Non-Regulated Toxicology
October 18, 2016This one-hour webinar, led by IIVS Director of Quality and Compliance, introduces some of the concepts of Good Laboratory Practices (GLPs) designed to promote study and data integrity within an in vitro toxicology framework. Applying these concepts within your own laboratory should aid in production of robust, repeatable studies. View Slides...
Human Cell Line Activation Test (h-CLAT, OECD 442E)
August 24, 2016The human Cell Line Activation Test (h-CLAT) is a cell-based assay that identifies skin sensitizers by examining changes in the expression of cell surface markers (CD54 and CD86) implicated in dendritic cell activation, the third key event of the skin sensitization AOP. Following exposure of the THP-1 human monocyte cell line to the test substance, expression levels of CD54 and CD86 are quantified by flow cytometry and compared to controls. The method has been reviewed by the European Union Reference Laboratory for...
Direct Peptide Reactivity Assay (DPRA, OECD 442C)
August 24, 2016The DPRA (OECD 442C) is an in chemico assay that models the first key event in the skin sensitization Adverse Outcome Pathway (AOP) - skin, protein reactivity. Compounds implicated in causing Allergic Contact Dermatitis (ACD) are generally electrophilic in nature. This assay identifies dermal sensitizers based on their reactivity with synthetic peptides containing the nucleophilic amino acid residues lysine and cysteine. Using LC/UV, conjugation of the test material with the peptides can be analyzed. Trained by the developers of this assay (Procter & Gamble), IIVS...
Dermal Irritation Time to Toxicity
August 24, 2016Product development/product stewardship scientists and formulators typically find it desirable to compare or rank order the skin irritation potential of candidate formulations, or to monitor the impact of changes in formulations or ingredients on skin tolerance. Foremost, industry researchers need timely, accurate, cost-effective test results to help them get safer products to the marketplace. The Dermal Irritation Screening assay using a Time-to-Toxicity (ET50) protocol coupled with IIVS’ expertise in the methods help researchers meet their testing goals. The assay is designed...
Skin Irritation Test (SIT, OECD 439)
August 24, 2016Skin Irritation Test (SIT) in a Reconstructed Human Epidermis (RhE) Model Skin Irritation in the regulatory hazard classification and labeling context is defined as the production of reversible damage to skin following a defined chemical exposure. The Skin Irritation Test (SIT) is an in vitro, non-animal test designed to identify those chemicals and mixtures capable of inducing moderate skin irritation (UN GHS Category 2 Skin Irritants1), and to discriminate UN GHS Category 2 Skin Irritants from UN GHS 3 Mild Skin...
Short Time Exposure (STE, OECD 491)
August 24, 2016The Short Time Exposure (STE) assay, developed by Kao Corporation (Japan), is an in vitro assay used to assess acute eye irritation potential as an alternative to the traditional in vivo Draize test. The test method evaluates the cytotoxicity induced by a series of test chemical dilutions in a monolayer of rabbit corneal fibroblasts (Statens Seruminstitut Rabbit Cornea – SIRC) after a single five-minute exposure. Two prediction models were initially developed for the STE assay — one categorizes the test material as...
Eye Irritation Test using Reconstructed Human Corneal Epithelium (RhCE) Models (EIT, OECD 492)
August 24, 2016The Eye Irritation Test (EIT) is an OECD-approved in vitro non-animal test method for identifying chemicals and mixtures that may be irritating to the corneal epithelium. The test method utilizes an in vitro reconstructed human corneal epithelium (RhCE) model (EpiOcular™, MatTek Corp. or HCE, SkinEthic™), in an acute exposure assay to support international regulatory labeling requirements, according to the United Nations Globally Harmonized System of Classification and Labelling of Chemicals (UN GHS). The Eye Irritation Test can be used to support...