Parameters for evaluation of viability assays: accuracy, precision, specificity, sensitivity, and standardization

Area of Science:

• Cryobiology
• Cellular Biology
• Biotechnology

Background:

• Cryopreservation efficacy relies heavily on accurate viability assessment.
• A wide array of viability assays exist, but their selection requires careful consideration of tissue type and functional endpoints.
• Standardization and validation of these assays are paramount for reproducible results.

Purpose of the Study:

• To categorize and critically evaluate different classes of viability assays used in cryopreservation.
• To outline key factors for selecting and validating appropriate viability assays.
• To emphasize the importance of assay characteristics such as accuracy, precision, and statistical validity.

Main Methods:

• Classification of viability assays into seven principle groups: morphological, proliferation, metabolic, implantation, mechanical, motility, and DNA/RNA synthetic.
• Characterization of assays as qualitative, quantitative, or quantal, noting potential subjectivity.
• Discussion of critical factors for assay validation: accuracy, precision, standardization, specificity, sensitivity, statistical methodology, and assay range.

Main Results:

• Viability assays can be broadly categorized, each with inherent strengths and limitations.
• Assay selection must account for biological variability, assay bias, and statistical error probabilities (Type I and Type II).
• Robust validation parameters are essential for reliable cryopreservation assessment.

Conclusions:

• The choice of viability assay is a critical determinant of cryopreservation success.
• A systematic approach to assay selection and validation, considering multiple parameters, is necessary.
• Standardized and validated viability assays ensure the integrity and functionality of cryopreserved biological materials.