Understand AST Breakpoints With Ease
CLSI's annual antimicrobial susceptibility testing (AST) supplement, M100, has been updated and is now available. This document represents the most current information for drug selection, antimicrobial susceptibility test interpretation, and quality control. The data provided in M100 are relied upon throughout the world by laboratorians, infectious disease practitioners, and AST device manufacturers.
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M100 | Performance Standards for Antimicrobial Susceptibility Testing, 32nd Edition Print or PDF Nonmember Price: $180.00 |
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Looking for convenient packages of related performance standards? Purchase M02 and/or M07 with M100-Ed32 for additional savings.
M02 and M100 Package M07 and M100 Package M02, M07, and M100 Package
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M100-Ed32 Free (Available Friday, Feb. 18) |
M100 Plus (Available Friday, Feb. 18) |
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With this read-only web version of M100, you can now quickly reference the most trusted AST breakpoints from anywhere with an Internet connection. Available online as a convenient companion to our M100 document. | Get full online access to M100, M02, M07, and M11 with added functionality and fast, easy data searching in an electronic format. Plus, you’ll have the added benefit of quick access to related materials via an AST Resource Center. | Access CLSI's full library of standards—including M100—with eCLIPSE Ultimate Access, an enhanced, premium platform with advanced features to help you access standards quickly and easily. Included in some membership levels or purchased separately. |
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Webinar: Learn From the Experts

It is imperative for medical laboratories to incorporate these new recommendations into routine practice in order to optimize detection and reporting of antimicrobial resistance.
Learn the details of the new changes and what they mean for your organization in an important new webinar, presented by experts in the field of AST.
Wednesday, March 22, 2022 | 1:00-2:30 PM EST
or
Thursday, March 23, 2022 | 3:00-4:30 PM EST
Other Microbiology Documents
CLSI has a longstanding globally trusted reputation for its diligent development of Microbiology and AST standards and guidelines on test methods and QC procedures. Additionally, CLSI annually creates and revises AST breakpoints to meet global public health challenges related to antimicrobial resistance. CLSI’s library of Microbiology standards and guidelines establish vital performance criteria and best practice guidelines for use in the clinical microbiology laboratory field.
Rationale Documents
It’s important for medical laboratories, drug and device manufacturers, and regulatory and accreditation organizations to understand how antimicrobial susceptibility testing (AST) breakpoints and interpretive categories are determined. CLSI has published rationale documents that provide the scientific reasons behind our AST Subcommittee’s decisions, along with documentation of the standardized data and methods used to determine breakpoints.