当细胞被置于低渗环境中时,细胞外液的水分会顺着渗透压梯度进入细胞内部,导致细胞膨胀。在染色体核型分析等实验中,膨胀过程至关重要:①使细胞体积膨胀增大,细胞膜变得松弛。②将紧密聚集的中期染色体充分散开,避免重叠。③经过后续的固定和染色后,能在显微镜下获得分散良好、形态清晰的染色体图像,便于进行计数和分析。
低渗盐溶液 (0.075mol/L KCl)由氯化钾、去离子水等组成,为低渗溶液 (150mOsm/L),是一种在细胞生物学研究中常用的试剂,主要用于绒毛细胞、羊水细胞和实体瘤细胞的染色体制片和计数。该试剂仅用于科研领域,不适用于临床诊断或其他用途。
操作步骤 (仅供参考):
1、使用前,先将溶液恢复至室温。操作时应佩戴适当的防护用具。
2、以植物根尖细胞为例:
①将经过预处理 (如用秋水仙素处理)的如根尖分生组织切下。
②浸没于适量的低渗盐溶液 (0.075mol/L KCl)中。
③在25℃条件下处理约30min,37℃水浴处理10-15min。
④低渗处理完成后,吸弃低渗液。
⑤用固定液 (如甲醇:冰醋酸=3:1的混合液)室温下固定细胞30min,离心弃上清。
⑥加入适量的固定液,进行细胞重悬,并制作细胞薄片,用吉姆萨染色液染色。
⑦水洗,干燥后镜检。
注意事项:
1、低渗时间过长,细胞膜过早破裂,导致分裂细胞丢失或染色体丢失;低渗时间不足时,细胞膨胀不够,染色体分散不佳,难以进行染色体计数分析。
2、试剂开封后请尽快使用,以防影响后续实验效果。
3、为了您的安全和健康,请穿实验服并戴一次性手套操作。
When cells are placed in a hypotonic environment, water from the extracellular fluid enters the cells along the osmotic gradient, leading to cell swelling. This swelling process is critical for experiments such as chromosome karyotype analysis, for the following reasons: ① It increases the cell volume and loosens the cell membrane. ② It fully disperses the tightly clustered metaphase chromosomes to avoid overlapping. ③ After subsequent fixation and staining, well-dispersed and clearly morphologized chromosome images can be obtained under a microscope, facilitating counting and analysis.
Hypotonic Salt Solution (0.075 mol/L KCl) is composed of potassium chloride, deionized water, etc. As a hypotonic solution (150 mOsm/L), it is a commonly used reagent in cell biology research, mainly applied to chromosome slide preparation and counting of villus cells, amniotic fluid cells and solid tumor cells. This reagent is for research use only and not intended for clinical diagnosis or any other purposes.
Operating Procedures (for reference only)
1. Before use, allow the solution to return to room temperature. Appropriate protective equipment should be worn during operation.
2. Take plant root tip cells as an example:
① Cut off the pretreated (e.g., colchicine-treated) root tip meristem.
② Immerse it in an appropriate amount of hypotonic salt solution (0.075 mol/L KCl).
③ Incubate at 25℃ for approximately 30 minutes, or in a 37℃ water bath for 10–15 minutes.
④ After hypotonic treatment, aspirate and discard the hypotonic solution.
⑤ Fix the cells with a fixative solution (e.g., methanol: glacial acetic acid = 3:1 mixture) at room temperature for 30 minutes, then centrifuge and discard the supernatant.
⑥ Add an appropriate amount of fixative solution to resuspend the cells, prepare cell smears, and stain with Giemsa staining solution.
⑦ Rinse with water, air-dry, and observe under a microscope.
Precautions
1. Prolonged hypotonic treatment will cause premature rupture of the cell membrane, leading to the loss of dividing cells or chromosomes. Insufficient hypotonic treatment will result in inadequate cell swelling and poor chromosome dispersion, which will hinder chromosome counting and analysis.
2. Please use the reagent as soon as possible after opening to avoid affecting the results of subsequent experiments.
3. For your safety and health, wear a lab coat and disposable gloves during operation.