Key Updates to USP Chapters <2021> and <2022>
What You Need to Know for April 2026

The United States Pharmacopeia (USP) has updated microbial testing standards for dietary supplements to improve accuracy and efficiency. Key changes include:

• Extended APC incubation: Aerobic Plate Count (APC) is now 72 hours to better capture slower-growing yeast and mold
• New positive controls: Added to APC media to verify it supports growth of target organisms
• Faster coli testing: Enrichment time shortened to 18 hours (previously 24 hours) for quicker results

For more detail, refer to the official USP Compendial Notices for 2021 and 2022.

How We Support Safe, High-Quality, Compliant Products

Microbiology may not be the most visible part of manufacturing and product release, but it is one of the most critical. At Ara Testing Labs, we help food, beverage, and dietary supplement brands:

• Verify product safety
• Support environmental monitoring programs
• Evaluate shelf-life and product stability
• Maintain regulatory and quality compliance

Today we’re taking you inside our microbiology lab to walk through how we test, why we test, and how we confirm that both your product and our methods perform as expected.

Yes, there’s agar. Yes, there are Petri dishes. And yes, we captured it all so you can see how testing works in practice.

Our Microbiology Testing Capabilities

We offer multiple testing methods to give manufacturers flexibility based on cost, turnaround time, and regulatory requirements.

Agar Pour-Plate Methods
Includes USP <2021> and <2022>, FDA-BAM, and Compendial

Methods of Microbiology in Foods (CMMEF)

* Indicates testing included in our ISO/IEC 17025 scope of accreditation

Lot-Specific Positive and Negative Controls

Positive and negative controls are essential to verifying that microbiological testing performs as expected.

For each lot of culture media, we run controls before testing client samples:

• Positive controls confirm the method detects the target organism (growth or signal)
• Negative controls confirm the method does not produce false positives

This lot-by-lot verification helps prevent subtle media variability from impacting results.

The use of positive and negative controls are required by quality standards, including ISO/IEC 17025 (Clause 7.7), USP <1117> (Microbiological Best Laboratory Practices), and FDA guidelines.

Matrix Validation: Proving Your Product Doesn’t Hide Microbiology Organisms

Complex products (such as foods, beverages, and supplements) often contain ingredients that can interfere with microbiological testing. These may include:

To prevent false negatives, we offer matrix validation:

• We spike your product with a known control organism
• We test it using the same method used for routine testing
• We confirm the organism grows or is properly detected

This verifies that the method works within your specific formulation, not just under ideal lab conditions.