On April 1, 2015 the European Commission’s Joint Research Centre (JRC) announced it had published results of an interlaboratory comparison study on a method for assessing the cytotoxicity of nanomaterials (NMs). JRC considers the study to be an important step towards a harmonized method for toxicity screening of NMs. The Colony Forming Efficiency (CFE) assay is an in vitro method for the assessment of basal cytotoxicity. As the method is non-colorimetric and non-fluorescent, it avoids possible interferences of NMs with the toxicity assessments. The method was evaluated by 12 laboratories from the European Commission and France, Italy, Japan, Poland, Republic of Korea, South Africa, and Switzerland. A positive control (sodium chromate) and 9 NMs (e.g., gold, silver and silica nanoparticles) were tested. The undertaken interlaboratory comparison has shown the assay protocol to be well defined and easily and reliably transferable to other laboratories. The results obtained show good intra- and interlaboratory reproducibility of the assay for the positive control as well as the tested NMs. JRC thus recommends the CFE assay as the first method of choice within a battery of in vitro methods for the early toxicity screening of NMs.
JRC (April 1, 2015). “Towards a method for cytotoxicity screening of nanomaterials.”