Cytotoxicity Testing
Ensure your medical device meets global safety standards with our precise, ISO-compliant cytotoxicity evaluations.
Cytotoxicity testing is the critical first step in the biological evaluation of any medical device. Before expensive in vivo testing, you must demonstrate that your device does not damage mammalian cells. At EBI, we provide a comprehensive range of in vitro cytotoxicity assays according to ISO 10993-5, tailored to the specific nature of your material—whether it is an extractable liquid, a solid implant, or a novel biomaterial.
Why Choose EBI for Cytotoxicity Screening?
We understand that a „fail” at this stage halts your product launch. Our laboratory combines rigorous adherence to Good Laboratory Practice (GLP) with expert consultation. We don’t just send you a report; we help you understand the biological interactions of your device.
- Comprehensive Methodology: From qualitative visual grading to quantitative photometric analysis.
- Standardized Cell Lines: We utilize the industry-standard L929 mammalian fibroblast cell line.
- Regulatory Compliance: Reports ready for CE Mark (MDR), FDA, and MHLW submissions.
- Efficiency: Standard turnaround time of 4 weeks.
Our Testing Methodologies
We offer two categories of testing: Qualitative (Visual Grading) and Quantitative (Cell Viability %).
1. Qualitative Methods (Visual Grading)
These methods rely on expert visual inspection of cell morphology under a microscope. Grading is performed on a scale of 0 (No Reactivity) to 4 (Severe Reactivity). A grade of 2 (Mild Reactivity) or lower is required to pass.
MEM Elution Test
Best for: Devices where extracts need to be tested (e.g., permanent implants, prolonged exposure).
This is one of the most common biocompatibility tests. We extract potential toxins from your device using Minimum Essential Medium (MEM) supplemented with 10% Fetal Bovine Serum (FBS).
- Extraction: 24h or 72h at 37°C.
- Process: The extract is applied to L929 cells. Experts examine the cells at 24h and/or 48h and/or 72h intervals.
- Outcome: We look for cell lysis or morphological changes.
Direct Contact Test
Best for: Low-density materials or devices that contact tissue directly but cannot be extracted easily.
Instead of creating an extract, the test item is placed physically on top of the cell layer.
- Process: L929 cells are grown to sub-confluency. The device covers approx. one-tenth of the cell layer surface.
- Incubation: At least 24 hours at 37°C.
- Outcome: We assess the zone of cell death directly beneath and surrounding the sample.
Agar Diffusion Test
Best for: Transparent materials or delicate devices where direct mechanical pressure on cells must be avoided.
A layer of nutrient-supplemented agar acts as a cushion between the cells and your device.
- Process: The device is placed on top of the agar layer. Toxic substances, if present, diffuse through the agar to reach the L929 cells below.
- Incubation: 24 hours at 37°C.
- Outcome: Diameter of the decolorized zone (cell lysis zone) under the specimen using vital stains.
2. Quantitative Method (Viability Measurement)
This method eliminates subjectiveness by using photometric measurements to calculate the exact percentage of living cells compared to a control group. A viability of ≥ 70% is required to pass.
MTT Cytotoxicity
Mechanism: Mitochondrial Activity
This assay measures the metabolic activity of cells. Viable cells with active metabolism convert the yellow MTT tetrazolium salt into a purple formazan product.
- Process: Extracts are applied at various concentrations (100%, 50%, 33%, 25%).
- Readout: The intensity of the purple color is measured photometrically. Darker color = more healthy cells.
Sample Requirements
To ensure no delays in your testing, please prepare samples according to the ISO 10993-12 guidelines below based on the thickness of your material.
| Test Type | Material Thickness | Surface Area Required | Weight / Volume | Minimum Quantity* |
|---|---|---|---|---|
| MEM Elution | < 0.5 mm | 60 cm² | - | - |
| ≥ 0.5 mm | 30 cm² | - | - | |
| Irregular solid (high density) | - | 2 grams | - | |
| Irregular porous (low density) | - | 1 gram | - | |
| Liquid | - | 10 ml | - | |
| Direct contact | - | - | - | to be individually determined |
| Agar Diffusion | - | - | - | to be individually determined |
| MTT | < 0.5 mm | 60 cm² | - | - |
| ≥ 0.5 mm | 30 cm² | - | - | |
| Irregular solid (high density) | - | 2 grams | - | |
| Irregular porous (low density) | - | 1 gram | - | |
| Liquid | - | 10 ml | - |
* If the test item is not divisible (cannot be cut or isn’t a liquid/powder) and has absorbent properties an additional piece will be needed for the absorption test.
Note: For MHLW (Japan) submissions, please provide 8 grams or 120 cm² / 240 cm² depending on the specific test plan.
Standards & Compliance
Our laboratory conducts cytotoxicity testing in strict accordance with:
- ISO 10993-5: Biological evaluation of medical devices — Part 5: Tests for in vitro cytotoxicity.
- ISO 10993-12: Sample preparation and reference materials.
- GLP (Good Laboratory Practice) principles.
How We Work
Discovery & Insight
We begin with an in-depth consultation to understand your needs, challenges, and objectives. This helps us define the right strategy and scientific approach for your project.
Design & Development
Our experts translate your vision into actionable plans — combining innovative research, data, and technology to build precise and reliable solutions.
Delivery & Support
We implement the solution with full transparency and ongoing communication. After delivery, we stay involved — supporting you with optimization, updates, and future improvements.
FAQ: Common Questions about Cytotoxicity
Which method should I choose: MTT or MEM Elution?
If you are submitting for US FDA approval, quantitative methods like MTT are often preferred due to their objective data output. For general CE marking, MEM Elution (Qualitative) is widely accepted and cost-effective. We recommend consulting your Notified Body or letting our experts guide you.
What happens if my device fails the cytotoxicity test?
A cytotoxic result (Grade 3/4 or <70% viability) requires investigation. It may be due to detergent residues, manufacturing oils, or the material itself. EBI can assist with a failure analysis to identify the root cause.
Can you test permanent implants?
Yes. For permanent implants, we typically perform an extraction over 72 hours (instead of the standard 24 hours) to simulate prolonged exposure, ensuring strict safety compliance.
Which method should I choose: MTT or MEM Elution?
If you are submitting for US FDA approval, quantitative methods like MTT are often preferred due to their objective data output. For general CE marking, MEM Elution (Qualitative) is widely accepted and cost-effective. We recommend consulting your Notified Body or letting our experts guide you.
What happens if my device fails the cytotoxicity test?
A cytotoxic result (Grade 3/4 or <70% viability) requires investigation. It may be due to detergent residues, manufacturing oils, or the material itself. EBI can assist with a failure analysis to identify the root cause.
Can you test permanent implants?
Yes. For permanent implants, we typically perform an extraction over 72 hours (instead of the standard 24 hours) to simulate prolonged exposure, ensuring strict safety compliance.
Contact with us
We’re open to collaboration and research partnerships. Fill out the form — our team will respond as soon as possible.
Location:
Europejski Instytut Biomedyczny sp. z o.o.
ul. Bartycka 63A lok. 6, 00-716 Warszawa
Mail:
contact@ebi.bio
Phone:
+48 22 780 06 32
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