Sedia® HIV-1 Limiting Antigen (LAg)-Avidity EIA

Sedia® HIV-1 Limiting Antigen (LAg)-Avidity EIA

An in vitro single well quantitative limiting antigen avidity enzyme immunoassay for distinguishing recent HIV-1 infections from those which are long-term. Intended for use with liquid serum or plasma specimens.

For Research Use Only: Not for use in diagnostic procedures.

Gold Standard for Incidence

Independent evaluation by CEPHIA showed lowest false recency rate of any HIV incidence assay evaluated.*

*Kassanjee R, Pilcher C, Keating S, et al. on behalf of the Consortium for the Evaluation and Performance of HIV Incidence Assays (CEPHIA), Independent assessment of candidate HIV incidence assays on specimens in the CEPHIA repository. AIDS 2014 Oct 23; 28(16) 2439-2449. Read Assessment

Designed for Surveillance

Can be used to estimate HIV-1 incidence in a population, monitor and evaluate HIV intervention programs, and recognize those high-incidence populations. Ensures prevention research, vaccine trials, and resources are most appropriately utilized.


Catalog Number Description
1002 Sedia® HIV-1 LAg-Avidity EIA, For Research Use Only


Summary of Specifications
Assay Time 2-4 Hours
Processing Temperature 15° to 37°C (59° to 98.6°F)
Storage Temperature Refrigerator Pack: +2° to 8°C (35.6° to 46.4°F); Freezer Pack: -25° to -10°C (-13° to +14°F)
Specimen Type Human serum or plasma
Specimen Volume 5 µL
Custom Antigen Custom, multi-clade CDC “rIDR-M” HIV-1 gp41 antigen that provides for reduced HIV-1 subtype bias
Mean Duration of Recent Infection Approximately 130 days*
False Recency Rate Less than 1%**
U.S. CDC Qualified Each lot is performance tested by the U.S. Centers for Disease Control prior to market release
For Research Use Only Not for use in diagnostic procedures, RUO products are not to be used for diagnostic purposes, patient management, clinical purposes, or for investigational use within the U.S.
HIV Status Requirement Intended for use only with specimens previously diagnosed as HIV-1 positive

Custom Antigen

The assay incorporates a custom multi-clade CDC “rIDR-M” HIV-1 gp41 antigen that provides for reduced HIV-1 subtype bias. Mean duration of recent infection approximately 130 days.*

*Duong YT, Kassanjee R, Welte A, et al. Recalibration of the Limiting Antigen Avidity EIA to determine mean duration of recent infection in divergent HIV-1 subtypes. PLoS ONE 2015, 10(2)e0114947.

U.S. CDC Tested

Each Sedia® HIV-1 LAg-Avidity EIA lot is performance tested by both Sedia’s Quality Control Department and by the U.S. Centers for Disease Control prior to market release.

Certification of CDC testing can be provided upon request.

**Parekh B, Duong Y, Mavengere Y, et al. Performance of new LAg-Avidity EIA to measure HIV-1 incidence estimates and avidity maturation studies. PLoS ONE 2012, 7(3):e33328.

Independently Evaluated by CEPHIA

The Consortium for Evaluation and Performance of HIV Incidence Assays (CEPHIA) showed the Sedia® HIV-1 LAg-Avidity EIA displayed the lowest False Recency Rate of any HIV incidence assay evaluated. Read the assessment


Measure the incidence of HIV-1 as a tool for intervention programs.

Improve resource management and population surveillance.

Evaluate the success of HIV intervention programs.

Identify hot spots of new outbreaks of HIV infections.


The LAg-Avidity EIA Kit is made up of 2 packs. The Refrigerator Pack and the Freezer Pack.

    1. Refrigerator Pack contains:
      • 2x HIV-1 rIDR-M Coated Microwell plates
      • 2 x 10X Wash Buffer Concentrate
      • Sample Diluent
      • Dissociation Buffer
      • TMB Substrate
      • Stop Solution
      • Plate Sealers
      • Package Insert
    2. Freezer Pack contains:
      • Negative Control
      • Calibrator
      • Low Positive Control
      • High Positive Control
      • Goat Anti-Human IgG-HRP Conjugate
  • Polypropylene micro-dilution 1.2 mL tubes (“titer tubes”) in an 8×12 rack (e.g. Bio-Rad, +1-800-424-6723,, catalog number 223-9390;  or USA Scientific, +1-800-522-8477,, catalog number 1412-1000; or equivalent).
  • Polypropylene tubes with cap, 12-15 mL.
  • Graduated cylinders, beakers and flasks.
  • Serological pipettes with pipette bulb (or equivalent).
  • Positive displacement pipette or microliter syringe capable of delivering 5-20 μL (e.g. Hamilton Co., +1-775-858-3000,, 25 uL syringe catalog no. 7643-01, with needle, catalog no. 7770-02; or equivalent) to measure out Goat Anti-Human IgG-HRP conjugate concentrate.
  • Vortex Mixer.
  • Single-channel pipettes (2-100 μL) and multi-channel pipette (100-200 μL). Filtered tips are recommended for specimen handling.
  • Reagent reservoir (e.g. VWR International, +1-800-932-5000,, catalog number 53504-035 or equivalent).
  • Incubators, one each at 37°C (±2°C) and 25°C (±2°C).
  • Microwell Plate Washer, either 96-well or strip.
  • Spectrophotometer (Plate Reader) capable of reading 96-well plates at 450 nm with a reference filter at 620-650 nm.
  • Deionized or distilled water.
  • Household bleach (5-8% hypochlorite).
  • Personal protection equipment (PPE) (disposable gloves, safety glasses, etc.).
  • Biohazardous waste container.

Each test plate requires 11 wells be allocated for the controls and calibrator, thus allowing for the test of up to 85 specimens in screening mode. In confirmatory mode, up to 28 specimens can be analyzed.

Each lot is tailor-made and the components are qualified to work together. Individual components are not meant to be mixed with other lots of kits.

Kits are shipped in an insulated shipper containing ice packs. Immediately upon arrival, please store kits at recommended storage temperatures until they are ready to be used.

We offer a minimum shelf life of 12 months upon shipping.

Contact customer service at or by calling +1-503-459-4159.


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