Flow Cytometry
Virant Diagnostics offers specialized flow cytometry services, including Basophil Activation Testing (BAT) and Standard Immunophenotyping (SIP). Through rapid turnaround times, expert interpretation, and customizable testing solutions, our laboratory provides functional assessment of basophil responses and detailed characterization of immune cell populations to support clinician-directed allergy, immune reactivity, and immunodeficiency evaluations.
Basophil Activation Test for Allergy
Basophils play an important role in allergic inflammation. Basophil Activation Testing (BAT) is a specialized flow cytometry-based blood test that evaluates how a patient’s basophils respond after exposure to specific allergens or drug-related stimuli in the laboratory.
Because BAT evaluates live cell responses, proper specimen collection, handling, temperature control, and timely shipping are essential for reliable results. When interpreted together with the patient’s clinical history, symptoms, exposure history, and other allergy testing, BAT can support the evaluation of allergic and immune-mediated conditions and provide useful information for monitoring immune responses over time.
BAT results should be interpreted by qualified healthcare professionals and should not be used as a stand-alone diagnostic test.
Standard Immunophenotyping
Standard Immunophenotyping (SIP) is a flow cytometry-based test that identifies and characterizes immune cell populations and immune cell subsets. By evaluating the presence, proportion, and distribution of specific immune cells, SIP can help detect over- or under-representation of cell populations that may be relevant to immune system function.
Virant Diagnostics offers SIP to support the evaluation of patients with recurrent, unusual, or severe infections, as well as patients with known or suspected immunodeficiencies.
SIP results should be interpreted together with the patient’s clinical history, infection history, medication use, vaccine response when available, and other relevant laboratory findings. Results are intended to support clinician-directed evaluation and should not be interpreted as a stand-alone diagnosis.
Flow Cytometry Testing for Chronic Spontaneous Urticaria
Chronic spontaneous urticaria (CSU) is a recurrent skin condition characterized by hives, itching, and/or angioedema that occurs without an identifiable external trigger and persists for six weeks or longer.
Flow cytometry-based testing can provide valuable functional information by evaluating basophil activation and related immune responses. Results may be interpreted alongside clinical history, physical findings, serum tryptase, total IgE, thyroid autoantibodies, inflammatory markers, and other relevant laboratory data to help guide patient care and therapeutic decision-making.
Basophil Activation Test for Venom Allergy
Venom allergies can cause reactions ranging from large local swellings to severe systemic allergic reactions, including anaphylaxis.
Flow cytometry-based BAT evaluates how a patient’s basophils respond after exposure to specific venom allergens in the laboratory. BAT results should be interpreted together with the patient’s reaction history, serum-specific IgE, skin testing when appropriate, and the treating clinician’s assessment.
BAT is not intended to replace clinical judgment or emergency evaluation for severe allergic reactions.
Basophil Activation Test for Penicillin Drug Allergy
Penicillin and beta-lactam antibiotic allergies are among the most reported drug allergies. Clarifying drug allergy status can help clinicians make safer and more effective antibiotic choices, avoid unnecessary use of alternative antibiotics, and improve patient care.
Flow cytometry-based BAT measures whether a patient’s basophils become activated after exposure to selected drug-related stimuli. For penicillin drug reactions, BAT may provide supportive information, particularly in patients with a history suggestive of immediate-type hypersensitivity.
Because drug allergy diagnosis is complex, BAT results should be interpreted in the context of the patient’s clinical history, timing and features of the reaction, medication exposure, serum testing, skin testing when appropriate, and specialist evaluation.
Research & Publications
- Li H, et al. Basophil Activation Test Is An Effective Tool For Assessing The Outcome Of Peanut Oral Immunotherapy. Annals of Allergy, Asthma & Immunology. 2024 Nov;133(6) Suppl, S21.
- Chen J, et al. Monitoring Peanut Oral Immunotherapy Progress Using Basophil Activation Test (BAT) And Specific IgG4 Biomarkers. Annals of Allergy, Asthma & Immunology. 2025 Nov;135(5) Suppl 1, S81.
- Li H, et al. Monitoring Peanut OIT Response Using Basophil Activation Test In Patients with High Peanut- and Ara h2-specific IgE. Journal of Allergy and Clinical Immunology. 2026 Feb;157(2) Suppl, AB145.