At a glance
CDC provides materials and performance evaluation to help laboratories use the folate microbiologic assay to assess folate status in population surveys.
Overview
Low blood folate in women of reproductive age increases the risk for neural tube birth defects in their children. To implement appropriate interventions to reduce this risk and evaluate their effectiveness, public health officials can conduct surveys that assess folate deficiency and insufficiency in populations. Local or regional laboratory capacity to measure folate is necessary for reliable and comparable survey data.
The World Health Organization (WHO) recommends the folate microbiologic assay to assess folate status in population surveys (WHO, 2015). CDC's Nutritional Biomarkers Branch (NBB) and the CDC Foundation are collaborating to develop regional laboratory capacity to measure blood folate using this assay. The Bill and Melinda Gates Foundation through the Nutrition International Folate Task Team are funding this effort. The project identifies and enrolls proficient laboratories and assists new laboratories as they implement the assay.
CDC offers support and materials to laboratories conducting the folate microbiologic assay for epidemiologic use in population surveys including:
- Assay materials that support reliable and comparable data across laboratories and over time
- Performance evaluation program to assess assay performance and ensure continued proficiency of resource laboratories
CDC also supports the establishment of regional resource laboratories proficient in performing the folate microbiologic assay and available to analyze samples from other countries (Pfeiffer et al., 2018). Over time, these resource laboratories may expand their scope to other priority micronutrients beyond folate.
Training tools
- Folate Microbiologic Assay Training Manual
- Folate Microbiologic Assay Training Posters
- Part 1: Prepare Reagents
- Part 2: Set up and Dilute Samples
- Part 3: Prepare 98-Well Plates and Add Samples
- Part 4: Dilute Calibrator and Add to Calibrator Plate
- Part 5: Add Diluted Samples to Sample Plates
- Part 6: Seal and Incubate Plates for 42 Hours at 37˚C
- Part 7: Read Plates at 590 nm
- Part 8: Clean-up and Disposal
- Part 1: Prepare Reagents
Materials and resources
- Folate Microbiologic Assay Materials
- Performance Verification Program for the Folate Microbiologic Assay
- Quality Assessment Manual for Laboratories Using the CDC Folate Microbiologic Assay Kit
- Webinar on Folate Laboratory Capacity Building
- Framework for laboratory harmonization of folate measurements
References
Pfeiffer CM, Zhang M, Jabbar S. Framework for laboratory harmonization of folate measurements in low- and middle-income countries and regions. Ann N Y Acad Sci 2018; 1414:96–108.
World Health Organization. Guideline: optimal serum and red blood cell folate concentrations in women of reproductive age for prevention of neural tube defect. Geneva, Switzerland: World Health Organization, 2015.