Department of Pharmacology, Faculty of Science, Mahidol University, 272 Rama 6 Road, Bangkok, 10400, Thailand.
Department of Biotechnology, Faculty of Science, Mahidol University, 272 Rama 6 Road, Bangkok, 10400, Thailand.
Sci Rep. 2023 May 9;13(1):7505. doi: 10.1038/s41598-023-34570-5.
Conventional polarized light microscopy has been widely used to detect gouty crystals, but its limited sensitivity increases the risk of misidentification. In this study, a number of methods were investigated to improve the sensitivity of polarized light microscopy for the detection of monosodium urate monohydrate (MSUM) and calcium pyrophosphate dihydrate (CPPD) crystals. We found that coating glass slides with poly-L-lysine, a positively charged polymer, improved the attachment of crystals to the glass surface, resulting in clearer crystal images compared to non-coated slides. Additionally, the sensitivity of detection was further enhanced by selective dissolution, in which 40% v/v formalin phosphate buffer was employed to dissolve MSUM crystals but not CPPD while 10% ethylenediamine tetraacetic acid (EDTA) was employed to dissolved CPPD but not MSUM. The other possible interferences were dissolved in both EDTA and formalin solution. These methods were successfully applied to detect gouty crystals in biological milieu, including spiked porcine synovial fluid and inflamed rat subcutaneous air pouch tissues.
传统的偏光显微镜已被广泛用于检测痛风晶体，但由于其灵敏度有限，增加了误识别的风险。在这项研究中，我们研究了多种方法来提高偏光显微镜检测单水尿酸盐（MSUM）和焦磷酸钙二水合物（CPPD）晶体的灵敏度。我们发现，用带正电荷的聚合物聚赖氨酸涂覆载玻片，可以改善晶体在玻璃表面的附着，从而得到比非涂覆玻片更清晰的晶体图像。此外，通过选择性溶解进一步提高了检测的灵敏度，其中 40%v/v 福尔马林磷酸盐缓冲液用于溶解 MSUM 晶体，但不溶解 CPPD，而 10%乙二胺四乙酸（EDTA）用于溶解 CPPD，但不溶解 MSUM。其他可能的干扰物在 EDTA 和福尔马林溶液中溶解。这些方法已成功应用于检测生物环境中的痛风晶体，包括添加了猪滑膜液和发炎的大鼠皮下气囊组织。
