nAble Witness is mobile app designed for IVF labs to help prevent errors in identification of patients and their gametes and embryos. It uses data matrix bar codes which are compact and easy to print on small labels. By comparing the bar codes, the system verifies the patient identity and samples, and maintains a complete audit log for review and auditing the chain of custody along with photographic evidence. The App seamlessly interfaces with nAbleIVF for editing existing or creating new workflows. Designed for ease of use, the witness system adapts to any workflow and uses off-the- shelf components for cost-effectiveness and flexibility. It uses iPhone for reading the bar codes and recording images. Thus, each step of workflow and sequence followed are captured along with who performed with date and time stamp.