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Hematology

Kleihauer-Betke Test

Kleihauer-Betke Test is a Hematology laboratory test reference in the LabPedia Medical Laboratory Library. Acid elution stain estimating fetal red cells in maternal blood for fetomaternal hemorrhage (FMH) quantification; still used where flow-cytometric FMH assays are unavailable.

Also known asKB test; Acid elution test; Fetal cell stain

Overview

The Kleihauer-Betke test uses acid elution to remove adult HbA from maternal RBCs while HbF-containing fetal cells resist elution and stain darkly.

Clinical Importance

To estimate volume of fetomaternal hemorrhage after sensitizing events

To guide RhIG dosing when flow cytometry FMH is not available

Specimen Requirements

  • Maternal EDTA whole blood
  • Prepare thin smears promptly per protocol
  • Include control slides when available

Analytical Method

Acid buffer elutes HbA from adult cells (ghosts); HbF persists in fetal cells, which take up eosin stain. Fetal cells are counted to estimate FMH volume using a validated formula.

Instruments Used

Automated analyzers

  • Flow-cytometric HbF assays are preferred alternatives where available (not KB itself)

Manual methods

  • Manual Kleihauer-Betke acid elution stain with microscopic enumeration

Reference Values

Typical adult SI examples below follow widely published international hematology practice (e.g., Dacie and Lewis; Henry's). Always interpret against the method- and demographics-specific interval printed on the patient report (CLSI EP28-A3c). Neonatal, pediatric, pregnancy, and altitude intervals differ.

Normally few or no fetal cells detected in maternal blood.

FMH volume is calculated from fetal cell percentage using laboratory-validated formulas; not a single universal cutoff.

Interpretation

Common Causes of Increased Results

  • Increased fetal cells indicate FMH; calculate volume and communicate for RhIG dosing when applicable

Common Causes of Decreased Results

  • Negative/rare fetal cells suggest no significant FMH by KB sensitivity

Clinical Significance

  • FMH estimation
  • RhIG dose guidance when indicated

Factors Affecting Results

Pre-analytical

  • Poor smear quality; delayed processing
  • Maternal hereditary persistence of HbF confounding interpretation

Analytical

  • Subjective cell counting imprecision
  • Overstaining/understaining artifacts

Post-analytical

  • Calculation errors in FMH volume

Advantages and Limitations

Advantages

  • Widely taught; no specialized flow cytometer required

Limitations

  • Imprecise versus flow-cytometric FMH quantification
  • Confounded by elevated maternal HbF

Clinical Pearls

When precision matters for large FMH, prefer validated flow-cytometric fetal RBC quantitation if your laboratory offers it.

Related Laboratory Tests

References

Authoritative textbooks, guidelines, and reviews supporting this laboratory test reference. Verify reference intervals, critical limits, and method details against institutional protocols and current guideline editions.

Textbooks

  • McPherson RA, Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Elsevier; 2021.
  • Rodak BF, Carr JH. Rodak's Hematology: Clinical Principles and Applications. 6th ed. Elsevier; 2020.
  • Hoffbrand AV, Moss PAH, Pettit JE. Essential Haematology. 8th ed. Wiley-Blackwell; 2019.
  • McKenzie SB, Williams JL. Clinical Laboratory Hematology. 4th ed. Pearson; 2022.
  • Bain BJ, Bates I, Laffan MA. Dacie and Lewis Practical Haematology. 12th ed. Elsevier; 2017.
  • Kaushansky K, et al. Williams Hematology. 10th ed. McGraw-Hill; 2021.

CLSI and Professional Guidelines

  • Clinical and Laboratory Standards Institute. Defining, Establishing, and Verifying Reference Intervals in the Clinical Laboratory; Approved Standard. CLSI document EP28-A3c. CLSI; 2010.
  • Clinical and Laboratory Standards Institute. Management of Critical- and Significant-Risk Results. CLSI guideline GP47-Ed1. CLSI; 2015.

WHO Publications

  • World Health Organization. Guide to G6PD testing and counselling for safe use of 8-aminoquinoline drugs. WHO; 2022.

Frequently Asked Questions

Common questions about using this Kleihauer-Betke Test laboratory test Medical Laboratory Library reference in Medical Laboratory Science education.

What is the Kleihauer-Betke Test laboratory test reference used for?

This Medical Laboratory Library page summarizes the clinical importance of Kleihauer-Betke Test. Review the Clinical Importance section for why the test is ordered in laboratory medicine practice.

Where can I find Kleihauer-Betke Test specimen requirements?

See the Specimen Requirements section on this page for specimen information related to Kleihauer-Betke Test. Confirm collection details against your laboratory protocol.

Where are Kleihauer-Betke Test reference values listed?

See the Reference Values section on this Laboratory Library page. Reference ranges can vary by method and population, so verify intervals with your laboratory.

How do I interpret Kleihauer-Betke Test results?

Use the Interpretation section for laboratory interpretation framing, including increased and decreased result patterns when provided. Do not treat educational text as a patient-specific diagnosis.

What analytical method is used for Kleihauer-Betke Test?

See the Analytical Method section for principle and method notes. Method details may differ by instrument and institutional SOP.

Are related laboratory tests linked from Kleihauer-Betke Test?

Yes. The Related Laboratory Tests section lists connected references for continued lookup in the Medical Laboratory Library.

How can I continue learning after reading Kleihauer-Betke Test?

Use Continue learning links on this page for related Academy lessons, medical laboratory quizzes, or laboratory case studies when available for this Hematology topic.

What are the clinical pearls for Kleihauer-Betke Test?

See the Clinical Pearls section for concise laboratory practice notes associated with Kleihauer-Betke Test. Apply pearls alongside institutional protocols.

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