{'fraction_non_alphanumeric': 0.015309672929714684, 'fraction_numerical': 0.0055671537926235215, 'mean_word_length': 5.391111111111111, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
The ultrastructure of isolated glial (Müller) cells from the turtle retina

Sarthy and Lam (1978) described a method for isolation of glial (Müller) cells from turtle retina which involves papain treatment, mechanical dissociation of the retinae, and subsequent separation of the dispersed cells by velocity sedimentation at unit gravity. In order to establish the cytologic integrity and the extent of contamination, we have carried out ultrastructural studies on the isolated cells using scanning and transmission electron microscopy. During the course of these studies we have also examined the effect of papain on the morphology of the retina. Scanning electron microscopic studies show that the isolated cells have a free surface with limited extraneous material attached. The basal portion of the cell is organized as end bulbs with a convoluted surface while the apical region is specialized with long microvilli. Transmission electron microscopy shows that the isolated cells have intact plasma membranes with very few interruptions. The cytoplasm is dense and contains the normal complement of smooth endoplasmic reticulum, microtubules, and filaments. The extent of contamination as estimated from serial sections of a single cell is about 10–15% of the total cell volume. These studies indicate that Müller cells isolated by this technique should be useful for metabolic studies and for characterizing the Müller cell surface.