Data Integrity and Compliance
TL;DR
ALCOA+ is the set of nine attributes regulators use to decide whether lab data can be trusted: Attributable, Legible, Contemporaneous, Original and Accurate, plus Complete, Consistent, Enduring and Available. It applies to paper notebooks and electronic records alike, and the data integrity guidance from the FDA, MHRA and WHO is built around it.
ALCOA+ is an acronym for the nine attributes that make a record of lab data trustworthy: Attributable, Legible, Contemporaneous, Original, Accurate, Complete, Consistent, Enduring and Available. Regulators use it to judge whether data can support the decisions made with them, and it applies to a paper notebook just as much as to an entry in an electronic lab notebook.
The first five letters came out of the FDA. Stan W. Woollen coined ALCOA in the early 1990s while he was working in the FDA's Office of Enforcement, as a memory aid for his public talks as the agency's bioresearch monitoring coordinator. The four "plus" attributes were added later, once regulators started applying the idea to electronic records. The MHRA's 2018 GxP data integrity guidance lists all nine and says expectations are the same whichever acronym you use, and the WHO's 2021 data integrity guideline uses ALCOA+ throughout.
People often treat ALCOA+ and data integrity as the same thing. Data integrity is the goal, though, and ALCOA+ is what an inspector holds each record up against, one record at a time.
Each attribute comes down to a habit at the bench or a control in whatever system holds the record.
Original catches people out more than the others. If you write a cell count on your nitrile glove because there was no paper within reach, the glove is now raw data, strictly speaking.
Mostly in guidance documents, and in the wording of inspection findings. The FDA's 2018 guidance on data integrity in drug CGMP defines data integrity as "the completeness, consistency, and accuracy of data" and says such data should be ALCOA. The same guidance says it is not acceptable to record data on pieces of paper that will be thrown away once the values are transcribed into a laboratory notebook. That's the glove problem in regulatory language.
GLP has its own version of the same idea. For studies conducted under GLP, 21 CFR 58.130(e) says data are recorded directly, promptly and legibly in ink, dated and signed or initialed by the person who entered them, and changed only in a way that leaves the original entry readable, with a reason and a date.
So when an FDA warning letter cites data integrity, the finding usually maps onto one or more of the nine attributes. Original data that were not retained is a common one. A result nobody can trace to an analyst is another. And outside regulated work, these are the same attributes a PI relies on when a reviewer questions a figure. For records drafted or analyzed with AI tools, see what ALCOA+ means when AI is used in labs.
Pick one recent experiment, say a western blot from last month, and trace it from the notebook entry to the raw image files and then to the quantification spreadsheet. The gaps tend to show up fast: an image saved only as a cropped PNG or an antibody lot number that never got written down.
Then fix whatever depends on someone remembering. Retire shared logins first. Decide where raw instrument files live and who is allowed to delete them, and write a short correction procedure that keeps the original value visible next to the reason it changed. For electronic records, check that the audit trail is one users can't switch off.
In IGOR, the electronic lab notebook saves every edit as a timestamped version in Document Version History, and the audit trail attributes each change to the user who made it. Files uploaded to the Appendix widget are kept as the original, unaltered file. Approved entries are permanently locked, and correcting one means creating a revision copy with a documented reason.
ALCOA+ stands for Attributable, Legible, Contemporaneous, Original and Accurate, plus Complete, Consistent, Enduring and Available. The first five are the original ALCOA.
ALCOA+ adds four attributes to the original five: Complete, Consistent, Enduring and Available. They reflect problems that became more visible once labs moved to electronic records, deleted runs being the obvious example. The MHRA's 2018 guidance says expectations are the same whichever acronym is used.
Not as a regulatory requirement. ALCOA+ is an expectation for regulated work, such as studies conducted under GLP or manufacturing under GMP. But a journal editor or a patent attorney looks for the same attributes when a result is questioned, so academic labs gain from following it anyway.
No, a photo of a notebook page is a copy. It can stand in for the original only if it is verified as a true copy that keeps the full content and context of the page. The IGOR mobile app uploads photos of handwritten notes directly to the matching notebook entry.
Stan W. Woollen coined ALCOA in the early 1990s, while he was working in the FDA's Office of Enforcement. He used it as a memory aid in his talks as the FDA's bioresearch monitoring coordinator, and it spread through the quality assurance community from there.
This page is a general overview of ALCOA+ for lab scientists. It is not formal compliance or legal advice, and requirements for a specific study or product depend on the regulations that apply to it and on your organization's own procedures.