小中大[讨论贴]超净台里的酒精灯,有害无益?
所在的实验室有用于培养细胞的超净台,内置酒精灯一个。老师传授授说在打开培养瓶或培养液之前要用酒精灯的火焰快速的烧一下,目的是消毒,减少污染。自己很怀疑这样做的有效程度,因为瞬间的火焰不可能将瓶口的温度升高很多,又如何达到消毒的目的呢?
在网上搜索后找到一些资料,认为不应在超净台内使用火焰。现将其放到丁香园上供大家参考,希望有经验的同学给个说法,超净台内到底应不应该有酒精灯。
Open flames are not required in the near microbe-free environment of a biological safety cabinet. On an open bench, flaming the neck of a culture vessel will create an upward air current which prevents microorganisms from falling into the tube or flask. An open flame in a BSC, however, creates turbulence which disrupts the pattern of HEPA-filtered air supplied to the work surface. When deemed absolutely necessary, touch-plate microburners equipped with a pilot light to provide a flame on demand may be used. Internal cabinet air disturbance and heat buildup will be minimized. The burner must be turned off when work is completed. Small electric "furnaces" are available for decontaminating bacteriological loops and needles and are preferable to an open flame inside the BSC. Disposable sterile loops can also be used.
摘自:cuturl('http://www.cdc.gov/od/ohs/biosfty/bsc/BSC2000sec5.htm')
事实上使用酒精灯会造成空气对流,从而带起超净台面上的灰尘,反而增加污染的机会。更何况还增加了火灾的隐患。
摘自:cuturl('http://www.dxy.cn/bbs/post/view?bid=66&id=6028528&tpg=1&ppg=1&sty=1&age=0#6028528')
The flaming of lips of tubes and flasks must ALWAYS be done whenever culture liquid is to be poured from a container (e.g., pouring plates). Flaming should be routinely done when caps are removed from tubes during transfer of cultures. The purpose of flaming is not to sterilize, but to warm the tube and create warm air convection currents up and away from the opening. This "umbrella" of warm, rising air will help to prevent the entrance of dust particles upon which contaminating bacteria reside.
摘自:cuturl('http://structbio.vanderbilt.edu/chazin/wisdom/labpro/sterile.html')
受到加分的鼓励,把CDC这段生物安全柜的文章翻译了。错误之处,万望指正,谢谢。译文如下:
在生物安全柜几乎没有微生物的环境中,明火是不需要的。在开放的操作台上
(BSC之外),通过灼烧培养瓶口,可以创造一个向上的气流,预防携带微生物的尘埃坠落入试管或培养瓶。而在一个生物安全柜中,明火产生扰动气流,破坏了供向操作台面的洁净空气的流向。如果真的确实需要明火,可以使用装备控制火焰大小的微型灯具。这样,柜内空气扰动和加热效应会减少到最低。需要火焰的操作结束后,必须关闭灯具。另外,相对于在生物安全柜内使用明火,更好的选择是使用电气化的“熔炉”来消毒接种环和接种针。一次性的无菌环也是一个选择。