Scholten H J, Pierik R L M
Department of Horticulture, Wageningen Agricultural University, Haagsteeg 3, 6708 PM Wageningen, The Netherlands Fax no.: +31-3 17-48 47 09 E-mail:
Plant Cell Rep. 1998 Jan;17(3):230-235. doi: 10.1007/s002990050384.
Agars with different performance in bioassays were analysed for physical and chemical properties. Agars with the highest gel strength had the best performance. Good performance was also related to a low pH of a suspension of agars and to a low sulphur content. The diffusion rate of ions in gels differed between agars, but could not explain differences in agar performance. The time of autoclaving had a marked effect on the gel strength, however, without affecting the performance. Chemical analysis revealed large differences between agars. The best agars had a relatively low salt content. One of the best agars had an extremely high content of trace elements. Agar impurities, especially of the trace elements were tightly bound to the agars. Up to 30% of the Murashige and Skoog (MS) salts were also immobilized in the gel. At pH 4.2, less nitrogen and phosphate were available from the MS medium than at pH 5.7. Chlorine could be washed out completely and appeared to be a good marker for agar quality and purity. With AgNO, chlorine contamination could easily be visualized.
对生物测定中具有不同性能的琼脂进行了物理和化学性质分析。凝胶强度最高的琼脂性能最佳。良好的性能还与琼脂悬浮液的低pH值和低硫含量有关。不同琼脂凝胶中离子的扩散速率有所不同，但无法解释琼脂性能的差异。高压灭菌时间对凝胶强度有显著影响，但不影响性能。化学分析表明不同琼脂之间存在很大差异。最好的琼脂盐含量相对较低。其中一种最好的琼脂微量元素含量极高。琼脂杂质，尤其是微量元素与琼脂紧密结合。高达30%的Murashige和Skoog（MS）盐也固定在凝胶中。在pH 4.2时，MS培养基中可利用的氮和磷比pH 5.7时少。氯可以被完全洗出，似乎是琼脂质量和纯度的良好指标。使用硝酸银（AgNO），可以很容易地观察到氯污染。
