DLD Noradrenaline Elisa

Storage and Stability 
The kit is shipped at ambient temperature and is subsequently stable until the stated expiry date when stored between 2 – 8 °C. Once opened, the kit is stable until the expiry date. 
The shelf life of the ready-to-use reagents is indicated on the respective bottle label. The shelf life and storage conditions of the prepared reagents is stated under 6.1. 
Bring all reagents to room temperature before use and refrigerate immediately after use.

Sample Collection and Storage 
Plasma 
EDTA plasma samples are required for the assay. Physical and psychical stress usually causes a high increase of the catecholamine concentration. Therefore, it is recommended to let the patient rest for 20 to 30 minutes after the venepuncture and before collecting the blood sample. Haemolytic, icteric and especially lipemic samples should not be used for the assay, as false low values will be obtained with such samples. The plasma samples can be stored at 2 – 8 °C up to 6 hours. For a longer period (up to 1 week) the samples should be stored at -20 °C. 

Urine 
The total volume of urine excreted during a 24-hours period should be collected and mixed in a single bottle containing 10 – 15 ml of 6 M hydrochloric acid as preservative. Avoid exposure to direct sun light. Determine the total volume and take an aliquot for the measurement. For patients with suspected kidney disorders the creatinine concentration should be tested, in addition. Urine samples can be stored at -20 °C for at least 6 months.

Calculation of Results 
The concentration of the standards (x-axis, logarithmic) are plotted against their corresponding optical density (y-axis, linear). Alternatively, the optical density of each standard and sample can be related to the optical density of the zero standard, expressed as the ratio OD/ODmax, and then plotted on the y-axis. 
A good fit is provided with 4 Parameter Logistic (alternatively Log-Logit or Cubic Spline). 
The concentration of the controls and urine samples in ng/ml can be read off the standard curve directly without any further conversion. 
The read concentrations of noradrenaline in plasma samples have to be divided by 15 due to the use of 300 µl plasma sample in relation to 20 µl per standard. 
Noradrenaline: 1 ng/ml = 5.91 nmol/l 
Quality Control: Test results are valid only if the kit controls are within the ranges specified on the QC Certificate. Otherwise, the test should be repeated.