New 8-OHdG Check ELISA（Code: KOG-200SE）主要用于尿液和血清样品中8-OHdG的检测，本文介绍检测尿液样品8-OHdG浓度时需要注意的几点问题。

8-OHdG concentration of random urine varies depending on the time, exercises, individual variation, drinking water and other factors. For the accurate assessment of oxidative stress in living bodies, we recommend to correct data by following methods.

Urine samples for 8-OHdG assay should be stored frozen, and should be thawed by 37 °C for 1 hour or 4 °C overnight. If insoluble materials are shown in the samples please remove by centrifugation (2000-5000G for 10-15 minutes).

1) 24 hour pooled urine

24 hour urine may be the best way to measure urinary 8-OHdG. In addition, creatitine correction of 24 hour urine may be ideal.

2) Creatinine correction

[8-OHdG (ng/mg creatinine] = [8-OHdG (ng/mL)] / [creatinine (mg/mL)]

This correction method is widely used, and is one of the reliable methods. But urinary creatinine concentration will be affected by exercise or some diseases. Please take care not to use creatinine correction method for exercise related research and renal or muscle related diseases.

3) Excretion ratio correction

The results by this method show well correlation between that of creatinine correction method. In addition this method is not affected by creatinine, and suitable for exercise related research.

a) Please record the passing hours from the last urination.

   For example, the last urination was PM10:00 and urine is collected at AM8:15, the passing hour is 10.25 hours.

b) Please record the total urination volume when you collect urine.

   In healthy subjects, the urination volume may be between 150 and 700 mL.

c) Please record the body weight(kg) of the sunject.

d) Please measure 8-OHdG concentration of random urine.

[8-OHdG excretion ratio (ng/hour/kg)] = [8-OHdG (ng/mL)] * [urination volume (mL)] / [passing hour] / [body weight]

NOTE:

Please take care to record the passing hours and urination volume precisely, because errors in these records will affect the results. It is recommended to collect first morning urine.