OECD 471: Bacterial Reverse Mutation Test (Ames Assay)

OECD 471: Bacterial Reverse Mutation Test (Ames Assay)
OECD 471: Bacterial Reverse Mutation Test (Ames Assay)

Evaluate the mutagenic potential of a test article based on the reversion of selective growth mutations

OBJECTIVE:

The purpose of this study is to evaluate the mutagenic potential of a test article based on the reversion of selective growth mutations in several strains of Salmonella typhimurium bacteria and in Escherichia coli WP2 uvrA bacteria, in the presence and absence of S9 activation. This protocol is based on OECD Guideline for Testing of Chemicals: No. 471 – Bacterial Reverse Mutation Test and U.S. EPA Health Effects Test Guidelines OSCPP/OPPTS 870.5100 – Bacterial Reverse mutation Test.  MB Research Labs utilizes the test guideline recommended bacterial strains (E. coli WP2 uvrA , S. typhimurium TA97a, S. typhimurium TA98,  S. typhimurium TA100, and S. typhimurium TA1535).  More information available here.

Basis of the Method:

The test system will be exposed to the test article via the plate incorporation method, which has been shown to effectively detect a wide variety of mutagenic compounds. This assay is based on the methodology  originally described by Ames, et al. (1975) and updated by Maron and Ames (1983) and complies with the Guidelines.

Data Interpretation:

In general, a 2-fold increase with or without metabolic activation will be considered a positive response. Dose-related increases approaching a 2-fold increase will be deemed equivocal and a repeat test will be recommended.

Negative Results will be determined by the absence of a dose-related increase in all five tester strains, again taking into account toxicity of the test article as well as the quality checks of the assay.

Positive Results from the bacterial reverse mutation test indicate that the substance induces point mutations by base substitutions or frame shifts in the genome of either Salmonella typhimurium and/or Escherichia coli. Negative results indicate that under the test conditions, the test substance is not mutagenic in the tested species.

This study is conducted in accordance with the Good Laboratory Practices of the EPA, 40 CFR 160 and 792, FDA 21 CFR Part 58, and as specified in the OECD, Principles on Good Laboratory Practice, revised 1997.

References:

1. B. N. Ames, J. McCann, and E. Yamasaki. Methods for detecting carcinogens and mutagens with the Salmonella/mammalian-microsome mutagenicity test. Mutat Res 31 (6):347-364, 1975.

2. D. M. Maron and B. N. Ames. Revised methods for the Salmonella mutagenicity test. Mutat Res 113 (3-4):173-215, 1983.

3 L. D. Claxton, J. Allen, A. E. Auletta, K. Mortelmans, E. Nestmann, and E. Zeiger. Guide for the Salmonella typhimurium/mammalian microsome tests for bacterial mutagenicity. Mutat Res 189 (2 (Oct)):83-91, 1987.

4. K. Mortelmans and E. Zeiger. The Ames Salmonella/microsome mutagenicity assay. Mutat Res 455 (1-2):29-60, 2000.

5. OECD Guideline for Testing of Chemicals: No. 471 – Bacterial Reverse Mutation Test (July 1997)

6. U.S. EPA Health Effects Test Guidelines OPPTS 870.5100 – Bacterial Reverse mutation Test (August 1998).

Need A Quote?

Contact MB Research for more information on conducting an Ames Test (OECD 471).

California SB-1249 – Testing Solutions – In Vitro & Alternatives

Cali SB-1249
Cali SB-1249

California Cruelty-Free Cosmetics Act (California SB-1249)

On Sep. 28,2018, California Governor Jerry Brown signed the California Cruelty-Free Cosmetics Act (California SB-1249), a bill banning the sale of cosmetics that undergo animal testing, making California the first state to approve such a ban.

The California Cruelty-Free Cosmetics Act makes it unlawful for cosmetic manufacturers to sell any cosmetic in California if the final product or any component of the product was tested on animals and goes into effect Jan. 1, 2020.

Products that have undergone testing on animals before that date can still be sold in California.  Earlier in the month, the bill passed the state legislature after it was narrowed in scope.

Are You Ready With In Vitro Testing?

I Love In Vitro Toxicology
I Love In Vitro Toxicology

MB Research Labs is positioned to help manufacturers with a suite of in vitro and alternative (non-animal) tests for cosmetic safety testing.  MB has over 45 years of toxicology testing experience and over 25 years of testing using non-animal test methods.

www.mbresearch.com/cosmetics.htm

 

GHS Categories for Eye Irritation

OECD 405 – GHS Toxicity Categorization for Eye Irritation & CorrosionRolling the Die with Eye Categories?Rolling the Die with Eye Categories?

MB Research Labs has developed a Dual Assay System for Eye Irritation Categorization

The Organization for Economic Co-Operation and Development (OECD) has prescribed the use of a weight-of-evidence (WoE) analysis, integrated with a sequential testing strategy, for the classification of acute eye hazards.  The October 2017 revision to the Health Effects Test Guideline No. 405 outlines a stepwise strategy that includes Step 6, “Perform validated and accepted in vitro or ex vivo ocular test(s),” specifying only four possible tests:  three designed to identify severe eye irritation/ corrosion (GHS Category 1) and one to identify non-irritants (GHS No Category), the top-down and bottom-up approaches, respectively.  The GHS Category 2 (eye irritant) classification is impossible by any one bottom-up or top-down test.

Dual Assays

The EpiOcular™ Eye Irritation Test; EIT (OECD 492), as a bottom-up test, either determines a material to be No Category, or that it causes eye effects, but cannot discriminate between eye irritation, serious eye damage, and corrosion.

Conversely, the top-down Bovine Corneal Opacity and Permeability; BCOP Test (OECD 437), is used for ruling in or ruling out Category 1 effects (serious eye damage/corrosion).  By using a dual-assay/approach system – the combination of the EIT and BCOP test – we have determined, with a high degree of accuracy, GHS Acute Eye Hazard Category 2 chemicals that cause reversible irritation to the eye.

Double Elimination

A Double Elimination occurs when a BCOP test rules out GHS Category 1 (severe irritation/corrosion) and the EIT rules out GHS No Category (non-irritant), analysis of the combined results concludes the only other possible designation – Category 2 (irritant). The classification defaults to Category 2A for labeling and handling purposes because at present differentiation between category 2A and 2B cannot be made.  Using this approach, we correctly identified 87% of the Category 2A/B chemicals as Category 2 after testing 42 chemicals (nine, 15, and 18 in Category 1, 2A/B, and No Category, respectively).

As a result of this analysis, we are encouraged by the potential of the BCOP-EIT dual-assay system, coupled with WoE evaluation, to correctly assign unknowns into GHS Category 1, Category 2A, and No Category Acute Eye Hazards without the use of less predictive and more expensive in vitro tests.  Moreover, in keeping with the OECD’s recommendations, we predict that such a system would greatly reduce reliance on the Draize Rabbit Eye Tests.

For more info about MB Research.

#mbresearch #invitrotox

MB Research Goes to NYSCC 2018!

Back at it again with the NYSCC Supplier’s Day!

Cosmetic Safety Testing
Cosmetic Safety Testing

MB Research offers Quality In Vitro Testing for Cosmetics.
Visit MB Research @ Booth#1549 for the latest on In Vitro Cosmetic Safety Testing

New York Society of Cosmetic Chemists Supplier’s Day
May 15-16, 2018, Jacob Javits Convention Center, New York, NY
MB Research Labs is a leader in the use and development of in vitro and alternative toxicology test methods. We specialize in protocols for Eye and Skin Irritation, Corrosivity, Skin Sensitization, Genotoxicity, and Phototoxicity.

For more info about MB Research.

57th Annual Meeting of the Society of Toxicology – MB Research Labs

Join Us on the Riverwalk SOT 57th Annual Meeting MB Research
Join Us on the Riverwalk SOT 57th Annual Meeting
MB Research

Visit MB Research Labs in San Antonio, Texas Mar 11th-15th, 2018 for the SOT 57th Annual Meeting and ToxExpo.

Come on by Booth #550 to get the latest on In Vitro/Alternative Toxicology Testing and Research performed at MB Research Labs.

http://www.mbresearch.com  #mbresearch #invitrotox

10th World Congress on Alternatives and Animal Use in the Life Sciences, Seattle, Washington

In Vitro Toxicology, Not SciFi Anymore
10th World Congress on Alternatives and Animal Use in the Life Sciences

MB Research Labs is honored to be attending the 10th World Congress on Alternatives and Animal Use in the Life Sciences. We will be presenting several posters focusing on the use and development of in vitro and alternative toxicology methods that are used in our laboratories.

Scientific Posters presented by MB Research Labs on the Use and Development of In Vitro and Alternative Toxicology Test Methods

More Information on In Vitro and Alternative Testing….

In Vitro Eye Irritation Testing

In Vitro Eye Irritation Testing-MB Research Labs
In Vitro Eye Irritation Testing- MB Research Labs

In Vitro Eye Irritation Testing

Currently, it is generally accepted that no single in vitro eye irritation test will be able to replace the in vivo Draize eye test
to predict across the entire range of irritation for different chemical classes. Several labs (including MB Research) have been working on strategic combinations of several in vitro and alternative test methods within a (tiered) testing strategy that could replace the Draize Rabbit Eye Test.

Available In Vitro & Alternative Eye Irritation Test Methods

  • OptiSafe™In Vitro Eye Irritation Test
  • 3D Human Ocular Tissue Equivalent Systems – MatTek, EpiSkin
  • HET-CAM – Hen’s Egg Test – Chorioallantoic Membrane (HET-CAM)
  • Bovine Corneal Opacity and Permeability Assay (BCOP)
  • Porcine Cornea Reversibility Assay (PorCORA)
  • Chorioallantoic Membrane Vascular Assay (CAMVA)
  • Replacement Ocular Battery (ROBatt)
  • Keratinocyte/Fibroblast Viability Assay (Neutral Red or MTT)
  • Keratinocyte Proliferation (turnover) Assay

For more info on in vitro and alternative toxicology methods, please see: www.mbresearch.com.

QVC Safety Testing

Consumer Products Safety Testing
QVC Cosmetics and Consumer Products Safety Testing

Need to have a Toxicological Risk Assessment performed for your product before acceptance on QVC?

MB Research offers a wide array of tests available to determine the safety of your cosmetic, personal care or consumer product.  These economic standard in vitro protocols are the perfect set of tests that you may be required to perform.

Contact MB Research Now!

#mbresearch #invitrotox

 

OptiSafe – Non-animal Ocular Irritation Test

OptiSafe™ – Non-animal Ocular Irritation Test 

OptiSafe Eye Irritation TestingOptiSafe™ Ocular Irritation Test

MB Research Labs is now offering the new OptiSafe™ – an in vitro test method in which a test substance is applied to a semi-permeable membrane. Damage to macromolecules in the membrane is measured to assess the test substance’s potential to cause eye irritation.

OptiSafe™ Background Information

OptiSafe™ is an acute in vitro irritation test method used to determine the ocular irritation potential based of a test substances utilizing a set of biochemical tests (mostly performed in parallel; “multiplexed”) which evaluate the potential of the test substance ability to disrupt, denature and degrade biological molecules. These measured values are relevant to GHS and EPA standard ocular safety classification systems.

Evaluated Mechanisms of Ocular Injury and Prediction Models

Different ocular irritants including, acids/bases, alcohols/aldehydes/ketones, strong oxidants and reactive chemicals/mixtures, damage the cornea and other tissues through additive and/or synergistic chemical reactions and biophysical effects.

Evaluated mechanisms of injury include:

  • Denaturation of specific water insoluble polymers that model the phospholipid bilayer of cells (which can occur at the corneal epithelium and conjunctiva).
  • Direct denaturation of macromolecules that model ordered collagen (which can occur at the corneal stroma).
  • Indirect denaturation of molecules across a membrane via osmotic effects (osmotic effects across the corneal epithelium and stroma can damage the cornea).
  • Potential to damage tissue via excessive oxidation and reactivity (which can occur at the epithelium, stroma, conjunctiva and iris).
  • Potential to damage tissues via extreme buffering (which can occur at the epithelium, stroma, conjunctiva and iris).

NICEATM reviewed a validation study conducted by the OptiSafe™ test method developer, Lebrun Labs, and concluded that the study data indicated that the OptiSafe™ method compared favorably to other in vitroocular toxicity testing methods. NICEATM is currently coordinating a validation study of the OptiSafe™ test method to demonstrate the reproducibility of the method among Lebrun Labs and two naïve laboratories. The study received support from an NIEHS Small Business Innovation Research grant. The study is ongoing and is expected to be completed in mid-2018.

MB Research Labs is a primary testing source using OptiSafe™ and has been deeply involved in the validation of OptiSafe™.

Utility of OptiSafe™

OptiSafe™ can be used to determine the irritation potential of cosmetics, creams, and a wide variety of consumer products. Results are presented as GHS, EPA classifications, an ocular irritation score and class.

OptiSafe™ can be used for:

  • Screening Finished Products for Ocular Irritation.
  • Ocular safety testing during product development for knowledge based formulation. (Products that irritate do not last long in the marketplace).

The Advantages of OptiSafe™ include:

  • Accurate Ocular Irritancy Test
  • High Sensitivity for Mild and Moderate Irritants
  • Fast Results
  • 1 year shelf life
  • Neither uses nor harms animals

MB Research Labs performs many other in vitro eye and dermal irritation tests for screening of cosmetics, consumer products, pharmaceuticals and chemicals.

www.mbresearch.com

OptiSafe™ is a trademark of Lebrun Labs, LLC and used here with permission.

Test Article Characterization – A GLP Requirement

5 Key Points of Test Article Characterization (TAC)

Test Article Characterization
Good Laboratory Practices (GLP)

Identity

The name under which the article will be tested Include CAS number, lot or batch, if applicable

Composition

The list of ingredients making up the test article

Strength

The stated concentration of an active ingredient in a test article mixture

Purity

The fraction that is the active ingredient (relative to impurities), usually expressed as a percent

Stability

The duration for which the test article will remain undegraded under the storage conditions provided

Why is Test Article Characterization (TAC) necessary?

When a study is conducted according to the Good Laboratory Practices regulations (GLPs), providing characterization of the material to be tested (the test article) to the Testing Facility (MB Research) is required.

Do you have characterization of the test article (e.g., Certificate of Analysis, or similar)?

Yes – Please provide this to MB Research prior to study initiation (signing the protocol, beginning the experiment).

No –Select ‘no test article characterization’ on the Sponsor Request section of the MB Research protocol. No further action is necessary. Refer to the GLP Compliance section below.

If yes, was test article characterization/analysis performed according to Good Laboratory Practices (GLPs), Good Manufacturing Procedures (GMPs), or neither*?

 Please select GLP, GMP, or non-GLP/non-GMP on the Sponsor Request section of the protocol.

Does your TAC include all five of the following GLP-required parameters?

Yes – The study will be in complete GLP compliance. No further action is necessary.

No – Refer to the GLP Compliance section below.

Good Laboratory Practices (GLP) Compliance 


A GLP compliance exception statement appears in the study report when TAC –

(1) is not provided

(2) is not provided prior to study initiation (signing the protocol)

(3) does not include all five of the parameters, and/or

(4) is not performed according to GLPs

MB Research Labs is a contract GLP toxicology lab with over 45yrs of experience in chemical, consumer product and cosmetic safety assessment.

www.mbresearch.com

MB specializes in in vitro toxicology testing and development of alternatives to animal models for toxicological assessments.