Bx41 optical microscope

Preliminary identification of isolated microalgae was performed by direct samples microscopy of BG-11 culture (10 μL) between 10 to 14 days. Among forty isolated microalgae (Figure 2), a total of twenty-nine single-cell strains were identified by evaluation of morphologic traits (cell shape, size, chloroplast, pyrenoid, flagellum, and cells arrangement) using an Olympus BX41 optical microscope equipped with an Olympus DP80 CCD camera, based on standard morphological feature keys [42 , 43 ].

Fish samples from different parts were selected. The back sample was cut into 2 × 2 × 2 cm pieces, and the tail and abdomen samples were cut into 2 × 2 × 1 cm pieces. The meat pieces were put into the cryostat after embedding them in the OCT (optimal cutting temperature) compound. The temperature of the microtome was –20°C, and the thickness of the slice was set to 10 µm. After the slicing was completed, the samples were placed on a glass slide for HE staining. Finally, the sample was observed with the Olympus BX41 optical microscope, and the picture was recorded (He et al., 2015 (link)).
The calculation of the fractal dimension was based on the picture of the freezer, and the entire binarized image was covered with a square subframe having a length of ε. The length of the square subframe was determined to be 1/2, 1/4, 1/8, 1/16, 1/32, and 1/64 of the side length of the image in turn. The number of grids covering the muscle tissue of the sample was recorded as N(1/ε), y was set at ln N(1/ε), x = ln 1/ε; the regression analysis was performed on x and y. Here, the slope of the straight line was the fractal dimension of the fish slice, and the ice crystal area was calculated by the “Summarize” function on the frozen slice image using the ImageJ software.

The ileum sections were collected for histological analysis, washed with PBS 0.1 M, longitudinally opened, rolled up, and immersed in 10% buffered formaldehyde solution (Neon, Suzano, Brazil) for 24 h until tissue fixation. This material was embedded in paraffin, and sections of 4 μm thickness were stained with hematoxylin and eosin (HE). The histological inflammation score was examined by a pathologist and evaluated according to the Soares et al. [41 (link)] method. Histological images were captured by a BX41 optical microscope (Olympus, Tokyo, Japan) with a 20× magnification objective, and the morphometric parameters were evaluated by measuring 20 villi height and 20 crypt depth with the ImageJ 1.51j.8 software (National Institutes of Health, Bethesda, MD, USA).

The Raman measurements were performed on a Horiba Jobin Yvon XploRA ONE Raman spectrometer coupled to an Olympus BX41 optical microscope, using an excitation green laser 532 nm, with an average power of 20 mW at the sample. The laser beam was focused on the surface of the liquid sample with a 10X objective. The diameter of the laser spot was approximately 8–10 μm. The SERS spectra were collected from the 400 to 1800 cm^− 1 spectral range. The intensity of three Raman shift lines, 1002, 1237 and 1391 cm^− 1, after fluorescence subtraction, are used to compare with a calibration curve for the SERS obtained from SA Analytical Reagent grade. Next, to record the SERS spectra, 50 μl of a 2.5 × 10^− 3 M citrate-reduced Ag-NP were placed in an aluminum container, 100 μl in capacity, mixed with 25 μl of the centrifuged saliva sample. An equal volume of a reference SA solution was using in the calibration process previous to any measurement session. Further details on the calibration process are provided in [14 (link)].

Formalin-fixed, paraffin-embedded tumor tissues were cut into slices (5 µm thickness) and stained with standard hematoxylin and eosin (H&E). H&E tumor sections were visualized using an Olympus BX41 optical microscope. The tumor necrosis score was based on the histological evaluation of all tumor tissues and calculated as the percentage of necrosis: 0, no necrosis; 1, <25% necrosis; 2, 25–50% necrosis; 3, 50–75% necrosis; 4, >75% necrosis [46 (link)].

After MN arrays were applied to the dorsum of the mouse skin for 1 h, the treated skin was stained with trypan blue for 30 min before wiping residual dye from the skin surface with tissue paper. The mouse was euthanized and the skin sample was viewed under an Olympus BX41 optical microscope (Japan).

An Olympus^© BX41 optical microscope is used to characterize different areas of the sample after the intercalation process. The sample was removed from the EC cell, dried with nitrogen and placed below the microscope.