Figure 2. Quantification of intact photoreceptors based on different dissociation techniques. Immediately after seeded in culture, isolated intact photoreceptors were counted under transmitted light. A: The enzymatic treatment with gentle pipeting (Protocol A) isolated a large number of intact photoreceptors (arrows with big arch). B: The enzymatic treatment with gentle pipeting followed by centrifugation (Protocol B) isolated mostly cell bodies (arrows with small arch). Most of the outer segment structures were lost during the dissociation process. C: The non-enzymatic treatment with gentle pipeting (Protocol C) isolated mostly elongated outer segment structures or debris not attached to cell bodies (arrows with dotted line). D: Shown are the percentages of intact photoreceptors observed under transmitted light with respect to total of observed nuclei. Protocol A yielded a significantly higher number of intact photoreceptors compared to the other techniques (the asterisk indicates a p<0.001). Error bars represent the standard error of the mean. The scale bar represents 20 μm.