Elving L D, Bakkeren J A, Jansen M J, de Kat Angelino C M, de Nobel E, van Munster P J
Department of Medicine, University Hospital, Nijmegen, The Netherlands.
Clin Chem. 1989 Feb;35(2):308-10.
The influence of storage on urinary albumin concentration was prospectively studied with use of overnight urine specimens (Albustix negative) from 73 diabetic patients. From each urine sample four aliquots were taken. One was stored at 4 degrees C and assayed within two weeks, the other three were stored at -20 degrees C and assayed within two weeks and after two and six months. Albumin concentration was measured with laser immunonephelometry. The detection limit, 1 mg/L, suffices for the screening of diabetic patients for microalbuminuria. After storage for two and six months at -20 degrees C, significantly lower albumin concentrations were found. The difference was mainly caused by lower concentrations found in urine samples in which a precipitate had formed, which was the case in 22 and 25 samples, respectively. Thus, freezing of urine samples for determination of low concentrations of albumin may yield falsely low results. Urine samples are best stored at 4 degrees C and assayed within two weeks.
我们前瞻性地研究了储存对尿白蛋白浓度的影响，研究对象为73例糖尿病患者的过夜尿液标本（Albustix检测为阴性）。从每份尿液样本中取出四份等分试样。一份保存在4℃，并在两周内进行检测，另外三份保存在-20℃，分别在两周内、两个月和六个月后进行检测。采用激光免疫比浊法测定白蛋白浓度。检测限为1mg/L，足以用于糖尿病患者微量白蛋白尿的筛查。在-20℃储存两个月和六个月后，发现白蛋白浓度显著降低。这种差异主要是由于在分别有22份和25份样本中形成沉淀的尿液样本中发现的浓度较低所致。因此，冷冻尿液样本以测定低浓度白蛋白可能会得出错误的低结果。尿液样本最好保存在4℃，并在两周内进行检测。
