Chromosome visualization is a technique used in many modern applications such as classification, in situ hybridization and genetic improvements, etc. Algal biotechnology grew steadily into an important global industry. Dunaliella salina (Teodoresco, 1905) is a model microalgae having tremendous potential for production of carotenoids for commercial use. The chromosomal size of microalgae is very small, and techniques for karyotype analysis are still unclear. In this work, it tried to simplify the techniques and establish a detailed step-by-step protocol using Dunaliella salina as a model and proved the technique in Tetraselmis chuii (Stein, 1878) which can be reproducible. The most important points were considered in the techniques as metaphase resting, fixation, dehydration and rehydration, hydrolysis and preparation of chromosomes for microscopic observations. During standardization, various concentration and duration of colchicine treatment were tested for metaphase arrest, replaced ethanol for methanol during fixation and dehydration, used a rehydration solution before hydrolysis and observed acid, base and enzymes impact on partial hydrolysis process of the cells. Colchicine treatment was found to be species dependent, and optimum concentration was 0.1% for 6 h (h) for Dunaliella salina, and methanol proved better to dehydrate for the preservation of algal cells. The low 500 mM concentration of HCl, 30 mM KOH and 5% enzyme proved to be suitable for the hydrolysis process for algal chromosome visualization. The technique permits clear visualization and counting of the smallest chromosome from unicellular algae. This technique described detail step by step without ambiguity and steps can be adapted on a species-specific manner.

中文翻译：

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来自单细胞微藻的较小染色体的可视化

染色体可视化是一种在许多现代应用中使用的技术，例如分类、原位杂交和遗传改良等。藻类生物技术稳步发展成为一个重要的全球产业。盐生杜氏藻 (Teodoresco, 1905) 是一种模型微藻，具有生产用于商业用途的类胡萝卜素的巨大潜力。微藻的染色体尺寸非常小，核型分析技术尚不清楚。在这项工作中，它试图以盐藻为模型简化技术并建立详细的分步协议，并在 Tetraselmis chuii (Stein, 1878) 中证明了该技术的可重复性。技术中考虑的最重要的点是中期静息、固定、脱水和补液，用于显微镜观察的染色体的水解和制备。在标准化过程中，对不同浓度和不同时间的秋水仙碱处理进行中期停滞测试，在固定和脱水过程中用乙醇代替甲醇，在水解前使用复水溶液，观察酸、碱和酶对细胞部分水解过程的影响。发现秋水仙碱处理具有物种依赖性，对于盐生杜氏藻，最佳浓度为 0.1%，持续 6 小时 (h)，并且证明甲醇对于藻类细胞的保存更能脱水。500 mM HCl、30 mM KOH 和 5% 酶的低浓度证明适用于藻类染色体可视化的水解过程。该技术允许对来自单细胞藻类的最小染色体进行清晰的可视化和计数。