Neutral red uptake (NRU) assay for cytotoxicity assessment

We offer comprehensive test packages for verifying the quality of type II and type IIR face masks according to the EN 14683 standard. The tests included in the packages are required to label face masks with the CE marking. Medical face masks are divided into Types I and II according to their bacterial filtration efficiency. Type I masks are not intended for healthcare professionals, but for the public to prevent the spread of infectious diseases. Type II masks are further classified based on whether they are splash-resistant (Type IIR) or not (Type II). To comply with the European Standard EN 14683, Type II face masks must undergo the following quality tests: Bacterial filtration efficiency (BFE) - The ability of the face mask to filter the bacterium Staphylococcus aureus. The BFE is expressed as the percentage of colony-forming units (cfu) that have passed via aerosol through the facemask. If a face mask consists of two or more areas with different characteristics, these areas will be tested separately., Breathability (Differential pressure) - The amount of differential pressure required to draw air through a measured surface area at a constant flow rate., Microbial cleanliness (Bioburden) - The measurement of colony forming units per gram as per EN ISO 11737-1., Biocompatibility - The medical face mask manufacturer shall complete a biocompatibility evaluation according to ISO 10993-1 as a surface device with limited contact. The applicable toxicology testing regimen shall also be determined.. In addition to the above, Type IIR masks require the following test: Splash resistance - Performed according to ISO 22609, this test determines the ability of a face mask to resist penetration of splashes of liquid at different pressures.. The lower displayed price applies to the Type II mask test package, while the higher price also includes the splash resistance test required for Type IIR masks.

Cytotoxicity assessment is a crucial part of biocompatibility testing, which is performed to ensure that medical devices do not cause adverse reactions when in contact with the body. The assessment is required for practically all new medical devices to be approved in the EU (under the MDR) and the US (510(k) submission to the FDA). During cytotoxicity testing, the material's potential to damage or kill cells is assessed using in vitro methods. This involves exposing cultured cells to the material and observing any negative effects on cell health and viability. According to ISO 10993-5, cytotoxicity testing can be performed on an extract of the test material or the material itself, depending on the device type. The standard also lists several direct and indirect test methods. We can provide cytotoxicity tests using the methods listed below. Direct methods: Neutral red uptake (NRU) assay, MTT assay, XTT assay. Indirect methods: Filter diffusion, Agar diffusion. The displayed example price covers testing with the commonly used NRU method, performed under GLP. Please ask for a quote for your medical device.

The purpose of cleaning validation studies is to show that reusable medical devices can be reprocessed effectively between uses so that patients are not exposed to pathogens. Depending on the device’s intended use and classification, appropriate reprocessing steps may include cleaning, disinfection, and/or sterilization. For cleaning validation more specifically, the testing procedure consists of three steps: Simulated contamination with artificial soils that accurately reflect clinically relevant soils, such as blood and other bodily fluids. , Cleaning (manual and/or automated), carefully following the manufacturer's instructions for parameters such as detergents, cleaning tools, water quality, and temperature. , Inspection, both visually and using quantitative methods relevant to the test soil (e.g., proteins, total organic carbon, or hemoglobin), to assess whether residual contaminants remain on the device.. Successful cleaning validation is often sufficient for non-critical reusable devices, such as blood pressure cuffs, monitors, and clutches. Semi-critical and critical devices will require further disinfection and/or sterilization validation studies, which we can also offer. The displayed example price covers a manual cleaning validation study with 6 reprocessing cycles and cleanability evaluations with visual inspection & protein content measurement. Test protocol formulation and reporting are also included.

ISO 10993-23 is an internationally recognized standard for assessing the irritation potential of medical devices when they come into contact with skin, mucosal membranes, or subcutaneous tissues. Irritation tests performed according to the standard are commonly used to demonstrate compliance with EU MDR and FDA requirements. The appropriate testing approach is chosen based on the body contact site: Skin irritation tests evaluate whether a medical device or material causes localized skin irritation when it comes into direct contact with the skin. Testing can be conducted using in vivo or in vitro methods, depending on the device and the market area. , Intracutaneous reactivity tests apply to medical devices or materials that penetrate the skin or come into contact with deeper tissues. The goal is to determine whether extracts from such devices cause localized inflammatory responses in the dermis or subcutaneous layers.. The device itself is tested with a direct contact method, when possible. Alternatively, polar and non-polar solvents are used to prepare extracts that simulate potential leachables from the device. The displayed example price includes an in vivo direct skin irritation test performed under GLP. For a more accurate quote, do not hesitate to contact us with a description of your device and any additional requirements you may have for testing (e.g., market area, quality systems, in vivo vs. in vitro methods).

The biocompatibility of medical devices with breathing gas pathways is generally assessed according to ISO 18562 standards. Measurlabs offers tests according to this standard family, including the following: ISO 18562-2: Tests for emissions of particulate matter (PM), ISO 18562-3: Tests for emissions of volatile organic compounds (VOCs), ISO 18562-4: Tests for condensate volume and leachables from condensate. Our experts are happy to help with any questions related to the tests and prepare a quote for you. Contact us with your testing needs through the form below, and we will get back to you shortly.

The MTT assay is a quantitative study to determine the potential biological reactivity of a mammalian cell culture in response to a medical device extract. It is one of the in vitro methods outlined in standard ISO 10993-5 for evaluating the cytotoxicity of medical devices. For the assay, the test item is extracted in cell culture medium, and the cells are grown in tissue culture plates and exposed to the test item extract. The plates are incubated, after which cell viability is assessed by measuring the conversion of the yellow MTT by the mitochondrial reductase enzymes into blue-violet insoluble formazan.  As only viable cells convert MTT into formazan, the number of viable cells correlates with the color intensity of the resulting cell culture, which is determined by photometric measurements. The medical device is considered non-cytotoxic if 70% or more of the cells are viable when compared to a control sample.

The bacterial reverse mutation (AMES) test is used to evaluate the genotoxic effect of a medical device or its extract when in contact with a bacterial suspension. The test is conducted according to OECD 471 and ISO 10993-3 by exposing a bacterial suspension of Salmonella spp and Escherichia coli to 5 concentrations of the medical device or its pure extracts. The AMES test is a preliminary "screening test" for genotoxicity. A full genotoxicity evaluation usually includes testing the device with two in vitro methods, of which AMES is typically performed first. An additional in vivo method can be used if needed. Measurlabs can support you with the full genotoxicity evaluation. Please contact our experts for a quote.

Pyrogenicity assessment by ISO 10993-11 to evaluate the material-mediated pyrogenic (i.e., fever-inducing) potential of medical devices. Material-mediated pyrogenicity tests focus on non-endotoxin-related substances, including bacterial exotoxins, endogenous pyrogens, prostaglandin, neurotransmitters, and metal salts. These can be studied using in vitro assays, where the fever-inducing potential is evaluated using cells, or in vivo rabbit pyrogen tests, where the animal's body temperature is monitored upon exposure to device extracts. Measurlabs provides testing using the following methods: Material-mediated pyrogenicity - In vivo (rabbit), Material-mediated pyrogenicity - In vitro (MAT, Monocyte Activation Test). Please ask for a quote for your medical device. We also offer Bacterial endotoxin tests (ISO 11737-3) to evaluate endotoxin-related pyrogenicity.

Sterility testing measures the growth of microorganisms on a product after the product has been sterilized. ISO 11737-2 is a harmonized standard for evaluating the sterility of medical devices by the EU Medical Device Regulation, as well as an FDA-recognized consensus standard for supporting 510(k) submissions. A sterile device or product is free from viable microorganisms. The purpose of sterilization is to inactivate microbiological contaminants to transform devices from a non-sterilized to a sterilized state. Sterility can be assessed when defining, validating, or maintaining a sterilization process. Testing according to ISO 11737-2 includes method validation by determining the initial bacterial count of control suspensions and testing the suitability of the culture media for aerobic and anaerobic bacteria and fungi. Also, the suitability of the test for the specific product is assessed. This example testing package includes the following: Testing of 3 identical specimens, Detecting the presence of aerobic and anaerobic microbes and fungi (yeast and molds), Validation of the sterility determination technique, The results are given as negative (no growth observed) or positive (growth observed). The price includes one result per micro-organism per product.. We can also offer a custom sterility test package for your needs, especially for large sample volumes. Please ask our experts for a quotation and estimated turnaround time

The XTT assay is a quantitative test used to assess the potential cytotoxic effects of a medical device extract on mammalian cell cultures. It is one of the in vitro cytotoxicity methods described in ISO 10993-5. The test item is extracted in cell culture medium, and the cells are seeded in tissue culture plates and exposed to the extract. After incubation, cell viability is evaluated by photometrically measuring the enzymatic conversion of the XTT reagent into a soluble orange formazan dye. Because only viable cells reduce XTT, the amount of formazan formed directly reflects the number of metabolically active cells. A device is considered non-cytotoxic when cell viability is equal to or greater than 70% compared to an untreated control.