Alternative Test Methods:
Validation and Regulatory Status

Microsomal Aromatase Assays
(used in conjunction with either Pubertal Male In Vivo Assay or Adult Male In Vivo Assay).
Description and references

US:  Validated by EPA for identifying aromatase-inhibiting chemicals (2007)

US: The Endocrine Disruptor Screening and Testing Advisory Committee (EDSTAC) recommended that the EPA consider the use of these assays in a tier I screening test battery for the Endocrine Disruptor Screening Program (EDSP) (2007).

In Vitro Androgen Receptor Binding Assay (Rat Ventral Prostate Cytosol)
Description and references

US: Pre-validation by ICCVAM (2002); validation by EPA (2007)

US: The Endocrine Disruptor Screening and Testing Advisory Committee (EDSTAC) recommended that the EPA use androgen receptor assays in a tier I screening test battery for the Endocrine Disruptor Screening Program (EDSP) (2007).

Reduction
(A negative result in the tier I test battery is sufficient to classify a chemical as having  low or no potential to cause endocrine disruption, thus avoiding tier II animal tests)

Human Recombinant Estrogen Receptor -α Binding Assays
Description and references

OECD: Presently conducting validation

US: In 2003, ICCVAM recommended that recombinant estrogen receptor binding assays undergo validation studies, though they still require standardization. A 2006 addendum revised the original list of 78 substances recommended for validation.

OECD: Draft of new test guidelines proposed (two protocols)

US: The Endocrine Disruptor Screening and Testing Advisory Committee (EDSTAC) recommended that the EPA use estrogen receptor assays in a tier I screening test battery for the Endocrine Disruptor Screening Program (EDSP) (2007).

Reduction
(A negative result in the tier I test battery is sufficient to classify a chemical as having  low or no potential to cause endocrine disruption, thus avoiding tier II animal tests)

Stably Transfected Human Estrogen-α Transcriptional Activation Assay for the Detection of Estrogenic Agonist-Activity of Chemicals (using hER-HeLa-9903 cell line)
Description and references

OECD: Presently conducting validation (lead agency is ICCVAM)

OECD: Draft new TG 455 (2008)

Reduction
(A negative result in the tier I test battery is sufficient to classify a chemical as having  low or no potential to cause endocrine disruption, thus avoiding tier II animal tests)

Stably Transfected Transcriptional Activation (STTA) Assay for the Detection of  Estrogen Receptor Agonists and Antagonists (LUMI-CELL^TM ER Assay)
Description and references

US: ICCVAM is currently conducting an international validation study with ECVAM and JaCVAM.

OECD: Draft new Test Guideline expected by 2009

US: The Endocrine Disruptor Screening and Testing Advisory Committee (EDSTAC) recommended that the EPA consider the use of this assay in a tier I screening test battery for the Endocrine Disruptor Screening Program (EDSP) (2007).

Reduction
(A negative result in the tier I test battery is sufficient to classify a chemical as having  low or no potential to cause endocrine disruption, thus avoiding tier II animal tests)

H295R Cell-Based Steroidogenesis Assay
Description and references

OECD: Presently conducting validation
(lead agency is US EPA)

OECD: Draft new Test Guideline proposed

US: The Endocrine Disruptor Screening and Testing Advisory Committee (EDSTAC) recommended that the EPA consider the use of this assay in a tier I screening test battery for the Endocrine Disruptor Screening Program (EDSP) (2007).

Reduction
(A negative result in the tier I test battery is sufficient to classify a chemical as having  low or no potential to cause endocrine disruption, thus avoiding tier II animal tests)

CertiChem Inc. MCF-7 Cell Proliferation Assay of Estrogenic Activity
Description and references

US: An intralaboratory validation study has been initiated at CertiChem laboratories. ICCVAM has recommended that the assay be given a high priority for additional validation.

No information

Replacement

OR

Reduction