DRG CMV IgG Elisa kit

PRINCIPLE OF THE TEST 
The DRG CMV IgG ELISA Kit is a solid phase enzyme-linked immunosorbent assay (ELISA). Microtiter wells as a solid phase are coated with inactivated grade 2 Cytomegalovirus (CMV) antigen (strain AD-169). Diluted patient specimens and ready-for-use controls are pipetted into these wells. During incubation Cytomegalovirus (CMV)-specific antibodies of positive specimens and controls are bound to the immobilized antigens. After a washing step to remove unbound sample and control material horseradish peroxidase conjugated anti-human IgG antibodies are dispensed into the wells. During a second incubation this anti-IgG conjugate binds specifically to IgG antibodies resulting in the formation of enzyme-linked immune complexes. After a second washing step to remove unbound conjugate the immune complexes formed (in case of positive results) are detected by incubation with TMB substrate and development of a blue color. The blue color turns into yellow by stopping the enzymatic indicator reaction with sulfuric acid. The intensity of this color is directly proportional to the amount of Cytomegalovirus (CMV)-specific IgG antibody in the patient specimen. Optical density at 450 nm is read using an ELISA microtiter plate reader.

Storage and Stability of the Kit 
Unopened kits and reagents as well as opened reagents must be stored at 2 °C to 8 °C. The microplate must always be stored in the resealable aluminum pouch containing a desiccant. Do not open the pouch until it has reached room temperature. The microtiter plate consists of 12 individual strips. Each strip can be divided into 8 individual wells. Unused wells must be immediately returned to the aluminum pouch with the desiccant and stored again tightly resealed at 2 °C to 8 °C.

Sample Collection
Serum: Collect blood by venipuncture (e.g. Sarstedt Monovette for serum), allow to clot, and separate serum by centrifugation at room temperature. Do not centrifuge before complete clotting has occurred. Patients receiving anticoagulant therapy may require increased clotting time. 
Plasma: Whole blood should be collected into centrifuge tubes containing anticoagulant (e.g. Sarstedt Monovette with the appropriate plasma preparation) and centrifuged immediately after collection. 
Whole blood should not be frozen before centrifugation.

Calculation of quantitative Results 
In order to obtain quantitative results in DU/mL (DU = DRG Units) plot the (mean) OD values of Neg. Control and the 3 Standards 1, 2 and 3 on (linear/linear) graph paper in a system of coordinates against their corresponding concentrations (0, 10, 40 and 80 DU/mL) and draw a standard calibration curve (OD values on the vertical y-axis, concentrations on the horizontal x-axis). Read results from this standard curve employing the (mean) OD values of each patient specimen and control. All validated computer programs can be used, that provide the following function: 4 PL (4 Parameter Logistics). We use DRG regression program for Windows (4 parameter Rodbart regression). If other regression software is used, the obtained values have to be validated by the user.