Methyl blue

Saturated KCl, L-malic acid, sucrose, and glycerol solutions were used as osmolytes and gradient concentrations were set at 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100%, respectively. The mixed-age nematodes (300) were subjected to high osmotic pressure at 25 °C for 6 h. The nematodes treated with different concentrations of each osmolyte and those treated with distilled water were divided into two groups for methyl blue (Shanghai Macklin Biochemical, Shanghai, China, M812703-25 g) staining experiments [23 (link)] and rehydration experiments. In group one, the treated nematodes were washed with distilled water, stained with 0.5% methyl blue for 20 min, and then observed and counted with a DM500 microscope. methyl blue can stain dead nematodes while living nematodes cannot be stained. The number of non-stained nematodes was counted using the DM500 microscope, and the nematode survival rate after 6 h of hypertonic dehydration treatment was calculated. In group two, the dehydration-treated nematodes were washed with distilled water to remove the osmolytes from the body surface and rehydrated in distilled water for 12 h. After 12 h, the number of living nematodes was counted, and the survival rates were calculated.

A PSF ultrafiltration support membrane with a MWCO around 20 000 g mol⁻¹ was purchased from Hunan Keensen, China. Monomers including TMC (>99.0%) and PIP (>99.5%) for interfacial polymerization were purchased from J&K Products Catalog. Methyl blue, semixylenol orange, safranine T and neutral red, used as the dye molecules to evaluate the separation performance of the membranes, were purchased from MACKLIN. Analytical standard bovine serum albumin (BSA) was purchased from Shanghai Aladdin Reagent Company and used as a model foulant. All other chemicals were analytical reagents and used directly without further purification.