Guidance

Cystic fibrosis: screening laboratory handbook

This document explains the guidelines for laboratories screening newborns for cystic fibrosis (CF) in the UK.

• From: NHS England
• Published: 1 February 2014
• Last updated: 5 October 2026
  Show all updates

  1. 5 October 2026

     Updated IRT cut off values as of October 2026

  2. 5 January 2026

     Updated cut off for GSP equipment users

  3. 20 December 2024

     Updated the national cut-off values for the Genetic Screening Processor (GSP) analyser.

  4. 8 October 2024

     Added clarification that publication was previously published by Public Health England. Removed screening helpdesk information.

  5. 31 May 2022

     GSP figures in the standard protocol section of the lab handbook have been changed from 45 µg/L to 46 µg/L for cut-off A, and 55 µg/L to 56 µg/L for cut-off B. The accompanying flowchart (figure 1) has been updated to reflect these changes.

  6. 18 August 2021

     Reviewed and updated guidance, replacing the 2014 version.

  7. 1 February 2014

     First published.

Documents

Cystic fibrosis screening laboratory handbook

HTML

CF laboratory guide pathways: text versions

HTML

Details

The handbook sets out laboratory standards and guidelines for cystic fibrosis (CF) screening in newborn babies, covering:

• the CF screening protocol
• laboratory quality and performance
• pre-analytical factors
• the immunoreactive trypsinogen (IRT) assay
• genetic analysis
• reporting and communication of results
• programme monitoring and data collection
• the background to CF screening

The handbook also includes links to screening result template letters, follow up forms, and information for parents/carers.

This publication was previously published by Public Health England, which closed on 30 September 2021.