DLD Serotonin Elisa

Storage and Stability 
The kit is shipped at ambient temperature. Upon arrival, store the kit at 2 – 8 °C to keep it stable until its expiry date. Once opened the kit is stable until its expiry date. The shelf life of the ready-to-use reagents is indicated on the respective bottle label. For stability of prepared reagents refer to 6.1. Reagents must equilibrate to room temperature before use and refrigerated immediately after use.

Sample Collection and Storage 
Serotonin is particularly sensitive to light; therefore the samples should be stored cooled and in the dark after collection. Avoid repeated freezing and thawing of the samples. Patients should avoid food and substances that affect the serotonin levels before drawing the blood sample or before and during the urine collection, including, for example, avocados, aubergines, pineapples, bananas, plums, mirabelle plums, currants, gooseberries, kiwis, melons, tomatoes, walnuts and coffee and substances such as methocarbamol, mephenesin, paractamol, salicylates, MAO inhibitors, nicotine.

Serum 
The test can be performed with human serum. Hemolytic, lipemic and icteric samples should not be used. The samples can be stored up to 6 hours at 2 – 8 °C. For a longer storage (up to 6 months) the samples must be frozen at -20 °C 
Urine 
Both spontaneous urine and collected urine can be used. 
Collected 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 (Warning: Observe hazard warnings) as preservative. Avoid exposure to direct sun light. Store in the dark during collection. Determine the total volume and take an aliquot for the measurement. For patients with suspected kidney disorders the creatinine concentration should be determined in addition. Urine samples can be stored at -20 °C for at least 6 months. Do not use non-acidified urine collection.

Calculation of the Results 
The concentration of the standards (x-axis, logarithmic) are plotted against their corresponding optical density (y-axis, linear). When using analysing software, it is recommended to use the Four Parameter Logistic (4PL) Regression (alternatively: cubic-spline or logit-log). 
The concentration of the controls, urine and serum samples in ng/ml can be read directly from the standard curve.

Limitations of Method 
The result of the Serotonin Elisa is to be seen in connection with other diagnostic procedures and the anamnesis and the resulting questions. Samples measured above the highest standard must be diluted with distilled water and reassayed. The values of diluted samples must be multiplied by the appropriate dilution factor. 
Serotonin in EDTA-plasma can be determined for research purposes only.