IACUC Protocol Template:
Writing for First-Pass Approval

Why Most Protocols Get Returned

Studies show that approximately 60-70% of IACUC protocols are returned for revisions on first submission. The top reasons are not scientific — they are administrative: inadequate 3R justification, missing statistical rationale for animal numbers, and vague pain management plans. These are all preventable.

This guide provides a section-by-section template that addresses every common deficiency. Follow these eight steps and your protocol will have a significantly higher chance of first-pass approval.

Your research objectives are the foundation of the entire protocol. IACUC committees need to understand why animal use is necessary and what you expect to learn. Vague objectives lead to vague protocols, which lead to revision requests.

Your objectives section should include:

• Primary hypothesis: A single, testable statement that your study will evaluate
• Specific aims: 2-3 clearly defined aims, each tied to a specific set of experiments
• Primary and secondary endpoints: Measurable outcomes (tumor volume, behavioral score, biomarker level) with defined thresholds
• Justification for animal model: Why in vitro, in silico, or other non-animal alternatives cannot answer this question

This section is where most protocols fail. IACUC committees require statistical justification for every animal you request. Saying "we plan to use 20 mice per group" without a power analysis will almost certainly trigger a revision.

Include the following details:

• Species and strain: e.g., C57BL/6J mice, Sprague-Dawley rats, New Zealand White rabbits
• Sex and age: Justify single-sex studies or explain mixed-sex design
• Weight range: Specify acceptable range and rationale
• Total number by species: Sum across all experimental groups, controls, and breeding colonies
• Statistical power analysis: Report the software used (e.g., G*Power), effect size, alpha level, power (typically 0.80), and resulting sample size per group
• Justification for species: Why this species and strain is the appropriate model

The 3Rs — Replacement, Reduction, and Refinement — are the ethical cornerstone of every IACUC protocol. Your 3R documentation must be thorough and specific, not boilerplate. Reviewers can tell the difference.

Replacement

List every alternative approach you considered (cell cultures, organoids, computer models, invertebrates, etc.) and explain specifically why each one is insufficient for your research question. Generic statements like "no alternatives exist" will be challenged.

Reduction

Show that you are using the minimum number of animals necessary. Reference your power analysis from Step 2. Describe any strategies to reduce numbers further, such as within-subject designs, pilot studies to refine effect size estimates, or shared control groups.

Refinement

Detail every measure you will take to minimize pain and distress:

• Analgesia and anesthesia protocols (drug, dose, route, frequency, duration)
• Environmental enrichment (housing, social grouping, nesting material, etc.)
• Humane endpoint criteria (specific body condition score, tumor size limit, weight loss threshold)
• Post-procedural monitoring schedule

A detailed timeline shows the IACUC that you have thought through every step. It also helps reviewers understand the cumulative impact on each animal. Present your timeline in a day-by-day or week-by-week format:

• Day 0: Animal arrival, acclimation period (minimum 5-7 days for most species)
• Day 7-14: Baseline measurements, randomization, group assignment
• Day 14-28: Experimental intervention (drug administration, surgery, behavioral testing)
• Day 28-35: Data collection, terminal procedures, euthanasia
• Post-study: Tissue collection, necropsy, data analysis

For each procedure, specify who performs it, where it takes place, and what monitoring occurs. If a procedure requires anesthesia, include the full anesthetic protocol (induction, maintenance, recovery monitoring).

The USDA classifies all animal use into pain categories. Your protocol must accurately classify each procedure and provide appropriate justification:

For Category D and E protocols, provide explicit scientific justification explaining why anesthetics or analgesics cannot be used. Simply stating "drugs would interfere with results" is insufficient — cite specific literature or pilot data.

Euthanasia methods must comply with the AVMA Guidelines for the Euthanasia of Animals. For each species in your protocol, specify:

• Primary method: The preferred method (e.g., CO2 inhalation for rodents, injectable pentobarbital for larger species)
• Concentration and flow rate: For inhalant methods (e.g., CO2 at 30-70% volume displacement per minute)
• Exposure duration: Time to loss of consciousness and time to death
• Secondary method: Confirmation of death (e.g., cervical dissection, bilateral thoracotomy, exsanguination)
• Justification for non-standard methods: If using a method not listed as acceptable by AVMA, provide detailed scientific justification

Under PHS Policy and OLAW expectations, every person who handles animals must have documented training. Your protocol should include a table listing:

• Name and role: Principal Investigator, Co-PI, veterinarian, research staff
• Species-specific training: Hands-on training for each species used (e.g., mouse injection, rat surgery)
• IACUC orientation: Date of completion for institutional IACUC training module
• Occupational health: Enrollment in the institution's occupational health program
• Surgery training: For surgical protocols, document training in aseptic technique, anesthesia monitoring, and post-operative care

Training records should be current. Expired training certifications are a common deficiency found during IACUC semi-annual inspections and AAALAC audits.

After completing all sections, submit through your institution's IACUC management system. Then actively track the review:

• Designated review (1-2 weeks): Lower-risk protocols reviewed by a designated member
• Full board review (2-4 weeks): Higher-risk protocols reviewed at a convened committee meeting
• Revision requests: Respond within 5 business days to avoid delays; address every comment specifically
• Approval notification: Do not begin animal work until you receive written approval
• Annual continuation: Submit annual review by the anniversary date to keep the protocol active

Frequently Asked Questions