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类别: 实验室测试
产品名称:细菌计数板
规格型号:HD-825 |
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Bacteria Counting Chamber is a one piece construction ensuring durability and accuracy with a Thoma ruling on a single round plateau. The Bacteria Counting Chamber is used for bacteria and sperm counting. Cell Depth is 0.02mm. Usage Bacteria/Sperm Counts Cell Depth 0.02mm +/- 1% (1/50mm) Volume of 1 Square mm 0.02 Microliter Ruling Pattern Thoma, 1/400 Square mm Rhodium coated (bright-line) No Counting Technique : Thoma Counting assumes precise knowledge of the limit lines of the counting chambers used. These are shown in the illustration below. Each one of the small squares is 0.05 x 0.05 mm square, ie 1/400 mm2. This figure will be found printed onto the surface of the counting chamber. To ensure that cells which are on or along the limit lines are not counted twice or are not missed during the count, certain rules have to be observed (see illustration below – this illustration is for an Improved Neubauer, hence the triple lines, but the principle is the same for the Thoma).
The black cells are the ones which would be included in the count for that square, the white ones would not as they will be included in the count for the adjacent squares. The count should be started at the top left-hand corner and follow the direction shown by the arrow (see illustration). Counting may be enhanced with the microscopes illumination reduced.
Notes on Counting Use reduced microscope illumination for all chambers.
The difference of the counter cells in the large squares and the group squares must not exceed 10 cells. Double checks must be performed for all cell counts. After
counting the two counting nets the bottom counting net is to be counted in the same way as a check. When doing this it is to be ensured that the chamber has not dried out. This can be prevented by filling the bottom chamber only shortly before the count and not counting after the sedimentation time.
The difference between the totals of the counts for the two counting nets must not exceed 10 cells. The average value of the counts is then used in the calculation formula or multiplied by the corresponding factor.
计数板的使用
准备
准备计数时,磨光的表面小心地用擦镜纸擦干净。盖玻片也要擦干净。
盖上盖玻片在需要盖的周边区域需要用蒸馏水弄的微湿然后盖玻片要慢慢的从计数板的前端推入,直到盖玻片的前端边缘与计数板的划格子的区域处于同位。
注意:盖玻片是很容易坏掉的!
在外部支持和盖玻片之间的干扰线(牛顿环)的组成显示了盖玻片的准确位置。
计数板加样
取一个良好混合型的吸管并且放置一些初期的几滴液体。
把吸管的外部擦干然后保持吸管一定的角度直到小滴液体被吸管JD吸上去。然后这滴液体被放置在盖玻片和计数板之间。由于盖玻片和计数板之间的毛细管现象作用的结果,两个平面之间的缝隙被灌满。在溶液要满出击数板截面的边缘之前,马上移走吸管的JD。如果有可见气泡或者液体已经满出边缘并且进入其他的沟里,那么计数板就要擦干净并且重新加样。
计数
装载好的计数板被放置在显微镜台上然后计数格在低倍镜焦距中显示。高倍物镜要非常小心的操作,因为计数板比常规的要更厚。如果你不小心的话,会导致计数板或者物镜镜头的损伤。
如果可能的话,在作血细胞计数的时候使用机械平台的显微镜。显微镜的照明是重要的,太亮了会影响划格线的观察。光可以通过虹膜光圈减弱直到划得格子在背景中再次清晰可见。细胞/质粒的计数应该充分稀释到他们不再互相重叠,并且均匀的分配。
要完成计数检测需要扩大到期望的可见的细胞/质粒。细胞数量的计算推荐计数100方格作为排除少量的结果。
计数格在超过划线区域使用时需要均匀的分配,并且这个通过藉由三倍之数决定的方格支架在进入区段之内。
计数完100方格后总数除100(计数的方格数),来得到每格的平均值。乘稀释度,除1/4000(每个小方格的立方容积1/20 x 1/20 x 1/10 – 1/4000mm3)。这次计算得到的数字是原非稀释流质的每立方毫米的细胞数量。