Accelerating Time-To-Results in Microbial QC Testing by Combining Innovative Controls with Automated Detection Systems

Challenges in conventional microbial QC workflows

Conventional workflows frequently rely on laboratory‑maintained frozen cultures that must be thawed, expanded, enumerated, and verified. These preparatory steps can extend over one to two weeks, depending on organism growth rates and verification requirements. Such processes introduce substantial hands‑on time and depend on technical expertise to ensure consistency across batches. Variability can arise from differences in incubation conditions, media performance, or subtle shifts in strain phenotype over repeated passages. 

Additionally, traditional reference material preparation requires long‑term low‑temperature storage and careful tracking of passage number—factors that complicate documentation and can affect strain fidelity if not rigorously controlled. These challenges can propagate into QC test variability, potentially affecting detection limits, colony counts, and ultimately batch‑release timelines.

Accelerating time-to-results (TTR) with innovative technologies

Given the limitations of traditional culture‑based workflows, two complementary approaches have emerged to improve consistency, reduce manual effort, and support more rigorous microbial QC practices.

1. Precisely quantitated, single-use microbial QC controls

   One major contributor to variability in QC workflows is the need to manually revive and prepare working cultures from frozen stocks. This process introduces uncertainty in CFU recovery, passage number, and strain stability. Precisely quantitated, single‑use microbial reference materials like ATCC’s MicroQuant™ offer a way to control these variables.

   MicroQuant™ materials are manufactured under ISO 17034 accreditation and produced directly from authenticated ATCC source strains, avoiding passage‑dependent drift and differences introduced by local culturing practices. These preparations also rehydrate nearly instantaneously at room temperature, eliminating the multiday sequence of thawing, subculturing, and enumeration while reducing the burden of documentation associated with tracking culture histories. By delivering a known CFU input in a ready-to-use format, QC laboratories can standardize biological materials from the outset and improve overall assay reproducibility.

2. Automated platforms for rapid microbiology quality control testing and enumeration

   A second barrier in conventional QC workflows is the reliance on manual plate handling and visual endpoint reads. Automated imaging platforms, such as Rapid Micro Biosystems’ Growth Direct® System, help resolve these issues by integrating incubation, imaging, and enumeration into a closed, controlled process. 

   This system detects microcolonies through autofluorescence, enabling earlier identification of growth compared with human visual inspection, often cutting TTR in half. Automated imaging also reduces variability introduced by individual analysts and provides high‑frequency measurement of colony development over time. This shift toward automated, data-rich imaging enhances traceability and supports more robust method verification.

Combining the power of ready-to-use controls with automated testing

The powerful combination of standardized reference inputs with automated detection systems help overcome key limitations of traditional microbial QC by reducing preparation time, minimizing user‑dependent variability, strengthening traceability, and supporting more reproducible results. 

This combined framework sets the stage for the 2025 collaborative study between Rapid Micro Biosystems and ATCC, in which ATCC’s precisely quantitated MicroQuant™ controls were evaluated on the Growth Direct® automated microbial detection platform. The study examined how standardized microbial inputs perform within a fully automated detection workflow, highlighting why such integrated approaches are increasingly important for modern manufacturing environments.

• Reproducibility: MicroQuant™ preparations showed consistent CFU recovery and demonstrated strong correlation (R² > 0.9) between visual and automated enumeration on Growth Direct®.

• Detection performance: MicroQuant™ organisms were detectable on the automated system within 72 hours, with TTR ranging from 16-60 hours depending on the organism and media type. In contrast, traditional microbial QC methods typically require 3-7 days. This highlights the efficiency and rapid decision-making capability of the Growth Direct® system.

• Workflow effects: Use of standardized reference materials reduced the number of manual steps required during setup and enumeration, supporting greater reproducibility and simpler method verification.

When combined, standardized reference controls and automated microbial detection platforms create a streamlined, high‑confidence QC workflow that directly addresses the speed, variability, and traceability limitations of traditional methods. By reducing hands‑on preparation, improving consistency of biological inputs, and enabling earlier, automated detection, these technologies together support faster time‑to‑results and a more reliable pathway to product release. As manufacturing demands grow and regulatory expectations evolve, integrated QC solutions like these will become increasingly essential for maintaining efficiency and ensuring the highest levels of product quality.

To learn more about MicroQuant™ by ATCC, visit www.atcc.org/microquant

To learn more about Rapid Micro Biosystems’ Growth Direct System®, visit https://www.rapidmicrobio.com/solutions/growth-direct-system

Did you know?

ATCC's MicroQuant™ best-in-class controls support USP General Chapters <51>, <60>, <61>, <62>, <71>, <72>, and <1072>.

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