ASTM E1326-20 PDF

Full title and description

ASTM E1326-20 — Standard Guide for Evaluating Non‑culture Microbiological Tests. This guide provides recommended approaches for assessing the accuracy, selectivity, specificity, precision, and applicability of non‑culture (non‑conventional) microbiological test methods and instruments intended to enumerate or indicate microbial populations or activity in samples.

Abstract

This short guide helps producers, potential producers, and users of non‑culture microbiological tests determine suitability and limitations of such tests (for example rapid instruments, ATP methods, or other non‑culture indicators) by describing study design considerations, statistical analysis recommendations, and comparison approaches against accepted culture or alternative reference procedures. It highlights the need for appropriate statistical treatment (see referenced practices) and expert microbiological input.

General information

• Status: Superseded/revised (E1326-20 revised by ASTM E1326-25; E1326-20 is the 2020 edition of the guide).
• Publication date: January 12, 2020 (designation E1326-20).
• Publisher: ASTM International.
• ICS / categories: 07.100.10 (Medical microbiology / microbiological methods).
• Edition / version: E1326-20 (guide).
• Number of pages: 6 pages.

Scope

The guide is intended to assist investigators and producers in determining the applicability of non‑culture methods for processing different sample types and in evaluating accuracy and precision versus conventional reference procedures (for example heterotrophic plate count, MPN, or other accepted methods). It recognizes that culture methods do not recover all organisms and therefore describes when alternate reference procedures or complementary analyses are appropriate, and it provides general guidance rather than prescribing a single statistical protocol (users are encouraged to involve a statistician).

Key topics and requirements

• Definitions and classification of non‑culture (non‑conventional) microbiological tests.
• Design of comparative studies to assess accuracy, selectivity, specificity, and precision (recommendations to use established statistical practices such as Practice E691 and references to other relevant guides).
• Guidance on selecting appropriate reference/culture methods for correlation (HPC, MPN, spread plates, or other accepted procedures) and on interpreting mismatches between culture and non‑culture results.
• Discussion of limitations, sample‑type considerations, and the importance of microbiological expertise and appropriate controls.
• Recommendations to document limitations and intended applicability (sample matrix, detection limits, false positives/negatives, and expected precision/reproducibility).

Typical use and users

Used by test developers and manufacturers of rapid/non‑culture microbiological kits and instruments, laboratory method evaluators, quality assurance and R&D personnel in industries that monitor microbial contamination (water treatment, fuels, industrial fluids, pharmaceuticals, food processing, and environmental testing), and regulatory or procurement groups evaluating fit‑for‑purpose test methods. The guide supports both internal validation and comparative studies against accepted reference methods.

Related standards

The guide references and is commonly used alongside statistical and microbiological practices such as ASTM Practice E691 (precision statements and interlaboratory testing), Guide E1488, and other microbiological sampling and method practices (examples in the guide include Practices D5245, D5465 and related industry test methods). Users should consult the guide’s reference list for the full set of linked standards and procedures.

Keywords

non‑culture tests, nonconventional microbiological methods, rapid microbiology, test evaluation, accuracy, precision, specificity, selectivity, heterotrophic plate count (HPC), MPN, method validation, ASTM E1326.

FAQ

Q: What is this standard?

A: ASTM E1326-20 is a guide (not a test method) that provides recommendations for evaluating non‑culture microbiological tests used to enumerate or indicate microbial populations or activity.

Q: What does it cover?

A: It covers study design considerations, statistical evaluation approaches, comparison with conventional culture/reference methods, limitations of non‑culture techniques, and documentation of applicability and performance characteristics.

Q: Who typically uses it?

A: Developers and manufacturers of rapid or non‑culture test kits and instruments, laboratory scientists, QA/QC and R&D teams across industries that monitor microbial contamination, and organizations assessing or accepting alternative microbiological tests.

Q: Is it current or superseded?

A: The E1326-20 edition was published in 2020 and has been revised by ASTM E1326-25 (the 2025 revision). Users who need the most current normative text should consult the latest ASTM designation (E1326-25) for any changes since 2020.

Q: Is it part of a series?

A: It is a single guide within ASTM’s E35 committee portfolio addressing microbiological methods and is often used in conjunction with related ASTM practices and guides (E691, E1488, and other sector‑specific practices) rather than as part of a numbered series.

Q: What are the key keywords?

A: Non‑culture, nonconventional, rapid microbiology, method evaluation, accuracy, precision, selectivity, specificity, HPC, MPN, validation, ASTM E1326.