爪蟾卵母细胞膜渗透率检测服务Xenopus oocyte membrane water permeability assay

以爪蟾卵母细胞为异源表达系统，通过精准监测低渗溶液中细胞体积的动态变化，计算水通透系数（P_f值），定量评价水通道蛋白（Aquaporin / PIP）的通水功能，并可同步进行甘油、尿素等小分子通透性分析。Using Xenopus oocytes as heterologous hosts, we monitor dynamic cell volume changes in hypotonic solution and calculate the osmotic water permeability coefficient (P_f), quantifying the water-conducting function of aquaporins (AQP/PIP). Glycerol and urea permeability can also be assessed simultaneously.

检测原理：低渗溶胀法Principle: hypotonic swelling assay

爪蟾卵母细胞在等渗溶液（~200 mOsm）中保持稳定体积。当转入低渗溶液（~70 mOsm）时，跨膜渗透压差驱动水分子通过质膜内流，引起细胞体积增大。表达水通道蛋白的细胞水内流速率远高于对照（水注射）卵母细胞，体积增大速率与 P_f 值直接正相关。Xenopus oocytes maintain stable volume in isotonic solution (~200 mOsm). On transfer to hypotonic solution (~70 mOsm), osmotic pressure drives water influx, causing cell swelling. Oocytes expressing aquaporins swell far faster than water-injected controls; the swelling rate directly correlates with P_f.

中心采用高分辨率显微成像系统（10 fps 连续采集）精准追踪卵母细胞截面积变化，通过球形模型计算瞬时体积，拟合初始线性相（0–30 s）斜率得到 P_f 值，精度高、重复性好。We use a high-resolution microscopy system (10 fps continuous acquisition) to precisely track oocyte cross-sectional area. Volume is calculated by a spherical model; the initial linear-phase slope (0–30 s) is fitted to obtain the P_f value with high precision and reproducibility.

适用研究方向Research applications

水通道蛋白功能研究的全面解决方案Comprehensive solution for aquaporin functional research

植物质膜内在蛋白（PIP）Plant plasma-membrane intrinsic proteins (PIP)

拟南芥、水稻、玉米等植物的 PIP1 / PIP2 亚类水通道；水分利用效率、气孔调控、吸水根毛机制研究。PIP1/PIP2 subclasses from Arabidopsis, rice, maize; water-use efficiency, stomatal regulation, root hair water uptake.

动物水通道蛋白（AQP）Animal aquaporins (AQP)

AQP1–AQP13 等哺乳动物水通道的功能鉴定；肾脏尿液浓缩、脑水肿、角膜透明度相关研究；药物靶点验证。Functional characterization of mammalian AQP1–AQP13; kidney urine concentration, brain edema, corneal transparency; drug target validation.

甘油 / 尿素 / 小分子通透性Glycerol / urea / small-molecule permeability

部分水通道（如 AQP3、AQP7）可通透甘油和尿素等小分子（aquaglyceroporin）；通过同位素标记底物或荧光探针结合 P_f 检测，全面评估通道底物特异性。Some aquaporins (e.g., AQP3, AQP7) conduct glycerol and urea (aquaglyceroporins). Combining isotope-labeled substrates or fluorescent probes with P_f measurement provides complete substrate-selectivity profiling.

突变体功能验证Mutant functional validation

野生型与点突变体 P_f 的平行比较，鉴定孔道氨基酸残基（ar/R 选择性滤器）的功能贡献；临床相关突变的功能后果评估。Parallel P_f comparison of wild-type vs. point mutants identifies functional contributions of pore residues (ar/R selectivity filter); clinical variant functional consequence assessment.

标准服务流程Standard workflow

从目的基因到 P_f 数据报告From target gene to P_f data report

客户提供基因序列 / 质粒 / cRNAClient provides gene / plasmid / cRNA

载体构建与 cRNA 体外转录（可加入 GFP 标签）Vector construction & cRNA synthesis (optional GFP tag)

V-VI 期卵母细胞显微注射（50 nL / 个），ND96 孵育 1–3 天Stage V-VI oocyte microinjection (50 nL/cell), ND96 incubation 1–3 d

低渗实验：快速换液（200 → 70 mOsm），10 fps 显微录像Hypotonic challenge: rapid bath exchange (200 → 70 mOsm), 10 fps video

体积 – 时间曲线拟合，P_f 计算，共聚焦膜定位（如选做）Volume-time curve fitting, P_f calculation, confocal localization (optional)

参数Parameter	规格Specification
等渗溶液Isotonic solution	ND96（~200 mOsm）
低渗溶液Hypotonic solution	5 倍稀释 ND96（~40 mOsm）或定制渗透压5× diluted ND96 (~40 mOsm) or custom osmolarity
图像采集Image acquisition	10 fps，≥180 s，自动追踪截面积
P_f 计算P_f calculation	P_f = V₀ · (d(V/V₀)/dt) / (S · V_w · Δosm)
对照组Controls	水注射 + hAQP1 阳性对照Water-injected negative + hAQP1 positive control
交付物Deliverables	P_f 值（含统计分析）+ 代表性体积 – 时间曲线 + 完整技术报告P_f values (with statistics) + representative V-t curves + full report

精准测定你的水通道蛋白活性Precisely quantify your aquaporin activity

提供基因序列，我们完成 cRNA 制备、注射、低渗实验与 P_f 计算，并出具详细分析报告。Provide your gene — we handle cRNA preparation, injection, hypotonic assay and P_f calculation, delivering a detailed report.

咨询此服务Enquire cRNA 注射服务cRNA injection