The tissue engineering industry needs better methods for measuring viability of cells in scaffolds.  We are assembling a group of experts for a Working Group (WG) to advance measurement of cell viability in scaffolds.  Through the WG, we will identify appropriate assays and model scaffold-cell systems for advancement.  Robustness testing will be used to develop reliable protocols.  Interlaboratory testing will be used to reduce variability and to assess reproducibility.  ASTM standard test methods will be written and balloted. Results will be validated with orthogonal methods and new methods for measuring cell viability in scaffolds will be developed.