Smz800 stereo macroscope

Images illustrating the clearing steps of thick intestinal sample were obtained with the SMZ800 stereo macroscope, equipped with a digital camera DS-Fi and DS-U2/L2 USB (Nikon, Amstelveen, The Netherlands). Samples were illuminated with white light (3,000°K) and the images acquired with the NIS-Element software.

1.5 cm long intestinal sections were split into two groups. One group (n = 6) was depigmented during 45 min with an in-house DPG solution (patent pending); the other (n = 4) was used as a control and not depigmented. Either samples were placed in a home-made tank with a black-and-white stripe pattern below its glass bottom. Images were acquired on a SMZ800 stereo macroscope (Nikon, Amstelveen, The Netherlands) as described above. A first image was acquired with the sample immersed in a 0.2 M Tris solution as a reference. The Tris solution was then removed and replaced with our BRG5 clearing solution (patent pending). Images were acquired every 10 s during 5 min, then every 30 s during 5 min and finally every minute during 10 min. For each image, we calculated Michelson’s contrast C_M = (I_max−I_min)/(I_max + I_min) using the intensity measured on the black (I_min) and white stripes (I_max). Data were processed with PRISM (GraphPad, San Francisco, CA, USA) software and the half-life, t_1/2, and plateau value of the evolution of C_M with time extracted for either condition (depigmented vs. non-depigmented).