TSH Receptor Autoantibody ELISA Kit

Sample

Serum

Species Reactivity

Human

Detection Method

iELISA

Intended Use

The ELISA Assay Kit is for the semi-quantitative determination of TSH receptor autoantibody in human serum.

Contents of Kit

1. ELISA STRIP WELLS - READY TO USE
Strip wells are coated with TSH Receptor (96 wells in total) and supplied as 12 strips of 8 wells in a frame and sealed in a foil pouch with desiccant. Before opening the pouch, allow it to stand at room temperature (20-25°C) for at least 30 minutes. After opening, keep any unused wells in the original foil pouch with the desiccant (reseal with adhesive tape), place in the self seal plastic bag provided and store at 2-8 °C for up to 12 weeks.
2. START BUFFER - READY TO USE 1 × 10 mL
3. CALIBRATORS - READY TO USE 4 × 1.0 mL. 1, 2, 8 and 40 IU/L (units are NIBSC 08/204)
4. KIT NEGATIVE CONTROL - READY TO USE. 1 × 1.0 mL
5. KIT POSITIVE CONTROL - READY TO USE. 1 × 1.0 mL (see label for concentration range)
6. M22-PEROXIDASE - LYOPHILIZED. 2 × 6 mL (reconstituted) Reconstitute each vial with 6 mL M22-peroxidase reconstitution buffer. Store reconstituted M22-peroxidase at 2-8 °C for up to 12 weeks.
7. M22-PEROXIDASE RECONSTITUTION BUFFER - READY TO USE. 1 × 15 mL. Buffer for reconstituting M22-peroxidase.
8. TMB SUBSTRATE - READY TO USE. 1 × 15 mL
9. CONCENTRATED WASH SOLUTION -DILUTE BEFORE USE. 1 × 100 mL. Dilute 1:10 with deionized water and store at 2-8 °C until the expiration date of the kit.
10. STOP SOLUTION - READY TO USE. 1 × 10 mL. Contains 0.5 M H₂SO₄.

Storage

Store all components at 2-8 °C, and allow all reagents to come to room temperature (20-25 °C) before use.

Precision

Intra-assay and inter-assay precision data is presented below

Detection Limit

The limit of quantitation (LoQ) is 0.56 IU/L calculated as the mean of 20 determinations of the negative control plus ten standard deviations. It is recommended that results below the LoQ be reported as 'less than 0.56 IU/L'.

Sensitivity

Analytical sensitivity is 0.06 IU/L calculated as the mean of 20 determinations of the negative control plus 3 standard deviations.
HOOK EFFECT
Three serum samples were diluted as shown in the table below to determine if there was any Hook Effect. None was observed.

General Description

In 1956 Adams and Purves observed that the serum of patients with Graves' disease contained thyroid stimulating activity distinct from thyrotropin (TSH). Subsequent research suggested the possibility that autoantibodies in Graves' sera stimulated thyroid function by binding to the same cell surface receptor as TSH. Evidence for this concept was first provided by studies of the effects of Graves' Immunoglobulin G on the binding of TSH to its receptor on thyroid membranes. These studies demonstrated that TSH binding was readily inhibited in a dose-dependent manner by Graves' Immunoglobulin G and, furthermore, suggested that Graves' Immunoglobulin G contained antibodies to TSH receptors.
The TSH Receptor Antibody (TRAb) assay has utility in the differential diagnosis of Graves' disease, and the assay results may allow the clinician to suggest the most appropriate course of therapy upon initial diagnosis.
In studies, the incidence of TRAb in patients with confirmed Graves' disease ranges from 94 - 100%. TRAb was not detected in 21 normal subjects, 10 patients with multi-nodular goiter, 12 patients with Hashimoto's thyroiditis or 16 patients with rheumatoid arthritis.