Fluorescent tagging of TentaGel® M NH₂ Monosized Amino TentaGel Microspheres. 6-Carboxyfluorescein. N,N'-Disopropylcarbodiimide (0.32 g) was dissolved in dimethylformamide (10 mL). The amine-modified TG-beads (0.05 g) were swelled in dimethylformamide (10 mL), this was added to the solution along with 6-carboxyfluroescein (0.05 g). The solution was stirred for 3 hours at room temperature. It was spun down and cleaned with dimethylformamide (10 mL x 3) and then with ethanol (10 mL x 2). The product was then air dried and an orange powered was collected (TGCFluor100) (0.074 g, 74%). Samples TGCFluor100, TGCFluor73 and TGCFluor36 are made per amounts in table. The amine modified TG-beads (0.05 g) were swelled in dimethylformamide (10 mL), this was added to the solution along with Rhodamine B (0.05 g). The solution was stirred for 3 hours at room temperature. It was spun down and cleaned with dimethylformamide (10 mL x 3) and then with ethanol (10 mL x 2). The product was then air dried and a pink powered was collected (TGRhodB100) (0.03 g, 60%). Samples TGRhodB100, TGRhodB73, TGRhodB36, TGRhodB17 an TGRhodB1.7 are made per amounts in table. The illumination source was a CoolLED pE-300 ultra fluorescence microscopy Illumination System. Images were acquired using Leica Application Suite X software. Excitation 495nm and emission 525/50 nm. Excitation 515-560 nm and emission long pass 560-590 nm. A small sample of 6carboxyfluorescein tagged TG-beads in water were smeared onto a glass slide. This was placed on the microscope platform and visualised using a fluorescent lamp.