Department of Nephrology and Medical Intensive Care, Charité - Universital Hospital Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.
German Rheumatism Research Center Berlin (DRFZ), An Institute of the Leibniz Foundation, Berlin, Germany.
Cytometry B Clin Cytom. 2023 Nov;104(6):417-425. doi: 10.1002/cyto.b.22117. Epub 2023 Mar 7.
Kidney diseases are a major health concern worldwide. Currently there is a large unmet need for novel biomarkers to non-invasively diagnose and monitor kidney diseases. Urinary cells are promising biomarkers and their analysis by flow cytometry has demonstrated its utility in diverse clinical settings. However, up to date this methodology depends on fresh samples, as cellular event counts and the signal-to-noise-ratio deter over time. Here we developed an easy-to-use two-step preservation method for conservation of urine samples for subsequent flow cytometry.
The protocol utilizes a combination of the formaldehyde releasing agent imidazolidinyl urea (IU) and MOPS buffer, leading to gentle fixation of urinary cells.
The preservation method increases acceptable storing time of urine samples from several hours to up to 6 days. Cellular event counts and staining properties of cells remain comparable to fresh untreated samples.
The hereby presented preservation method facilitates future investigations on flow cytometry of urinary cells as potential biomarkers and may enable broad implementation in clinical practice.
肾脏疾病是全球范围内的一个主要健康关注点。目前，人们迫切需要新的生物标志物来非侵入性地诊断和监测肾脏疾病。尿液细胞是很有前途的生物标志物，通过流式细胞术分析已经证明了其在各种临床环境中的实用性。然而，到目前为止，这种方法依赖于新鲜样本，因为细胞事件计数和信噪比会随着时间的推移而降低。在这里，我们开发了一种简单易用的两步保存方法，用于保存尿液样本，以便随后进行流式细胞术分析。
该方案利用甲醛释放剂咪唑烷基脲（IU）和 MOPS 缓冲液的组合，实现对尿液细胞的温和固定。
保存方法将尿液样本的可接受储存时间从数小时延长至长达 6 天。细胞事件计数和细胞染色特性与新鲜未处理的样本相当。
本文提出的保存方法促进了尿液细胞作为潜在生物标志物的流式细胞术的未来研究，并可能使其在临床实践中得到广泛应用。
