Glass culture tubes with metal caps and labels
Growth medium, from media room or customized
Glass pipette tubes
Parafilm
Vortexer
Fireboy or Bunsen burner
Motorized pipette
Micropipettes and sterile tips
For a typical liquid culture, use 5 ml of appropriate medium. The amount in each tube does not have to be exact if you are just trying to culture cells for their precious DNA.
Streak an agar plate from glycerol stock. Incubate plates until colonies grow.
Most incubations with E. coli take place at 37°C. Often bacteria with temperature sensitive mutations need to be grown at 30° instead.
The reason you need to streak plates is to be certain that you are starting from a single clonal population of cells. In this case, colonies that are picked are assumed to arise from a single cell dividing to form the colony.
Agar plates are just the standard. There are many different plating media that can be used (i.e., blood agar).
Take your plates from the warm room. Take an aliquot of the antibiotic(s), if needed, from the freezer, and set it on the bench to thaw.
Flame a glass pipette, open the bottle of medium and flame the mouth, measure out the amount you need to fill your tubes, flame the cap and recap the bottle as quickly as possible.
Remove the tube cap, flame the top of the culture tube, pipette in 5 ml, flame the top of the tube, and cap it.
Pick up one colony by tapping a small (0.1 μl) pipette tip (held on a pipette) on the surface of the plate. Uncap a tube, flame the top, tip the tube so as to transfer cells from the pipette tip to the surface of the media without touching the inside of the tube with the non-sterile portion of the pipetter, flame, cap. You can also use a sterile toothpick for transfer.
Often people use just a sterile metal loop (sterile by flaming) to place the colony in the tube. This is because flaming assures the sterility of the loop, whereas disposables such as pipette tips and toothpicks can be contaminated, and cannot be flamed on the spot.
Pipette the desired amount of antibiotic into each tube along the wall. Do not put the non-sterile part of the pipette inside the tube and use a new tip for each tube.
Vortex each tube for 1-2 seconds to mix well.
Take the tubes to incubate. Turn the rotating rack off using the dial to decrease the speed. Do not use the switch because the stop will be too abrupt. Add your tubes in a balanced layout. If you have an odd number, use extra empty tubes for balance. Turn the rotation back on to 7 (applies to MIT building 68 5th floor warm room). Do not forget to turn the rack back on.
Incubation once again is often at 37°C in an incubator or warm room.
Wait overnight or until your cells have reached the desired concentration.
The amount of time you wait depends on the reason for growing the cells. To miniprep plasmid DNA, an overnight culture is sufficient. However, when doing measurements of protein levels, take care to take readings at the same cell culture density each time.
美国宾夕法尼亚大学佩雷尔曼医学院科研人员发现,蚂蚁的血脑屏障在控制其行为方面起着积极的作用。血脑屏障可以调节蚂蚁大脑中的激素水平,从而影响他们在蚁群中的行为。相关研究成果发表在《Cell》杂志上。研究......
RNA引导系统利用引导RNA和靶核酸序列之间的互补性来识别遗传元件,在原核生物和真核生物的生物过程中都起着核心作用。例如,原核CRISPR-Cas系统为细菌和古细菌提供了对外来遗传因子的适应性免疫。C......
大约700万年前,人类从我们最接近的动物亲戚黑猩猩那里分离出来,在进化树上形成了我们自己的分支。在此后的时间里---从进化的角度看是短暂的---我们的祖先进化出了使我们成为人类的性状,包括比黑猩猩大得......
生命起源于一颗受精卵。精子“翻山越岭”遇见卵子的能力,是生命发生的必要条件。如果精子的运动能力出现异常,自然受孕的成功率便会大大降低;当精液中精子向前运动的比例低于32%时,则被定义为“弱精症(ast......
多细胞生物在发育过程中,存在着多种预定的、受到精确控制的细胞程序性死亡,例如细胞凋亡(Apoptosis)、程序性坏死(Necroptosis)、细胞焦亡(Pyroptosis),以及铁死亡(Ferr......
近日,国际学术期刊Cell子刊CellReports刊发了中国科学院海洋研究所在海洋动物细胞程序性死亡方面的最新研究成果。 皱纹盘鲍细胞焦亡激活通路及免疫调控示意图 海......
步入夏天,又到了减肥的“黄金时节”。提及减肥,无外乎于“管住嘴,迈开腿”。现有减重指南中提到,成年人在减肥时,需要每天通过运动+减少食物摄入的方式来消耗500-600千卡的热量,其中运动消耗就要达到3......
长久以来,剪接体的调控机理是怎样的,它们在细胞内部的动态组合和变化是怎样的,深深地吸引着科学家们的研究兴趣,但其神秘的面纱一直未被揭开。2023年4月6日,西湖大学施一公团队在 Molecu......
目前,研究人员对于明确和稳定细胞亚型背后的分子机制仍然知之甚少。近日,一篇发表在国际杂志CellMetabolism上题为“Epigeneticdosageidentifiestwomajorandf......
我们对记忆的起点和终点有一个很好的概念---短期记忆在海马体中形成,如果情况需要,就会在大脑皮层中稳定为长期记忆。但是,在短期记忆到长期记忆之间的曲折路径上发生了什么,却是一个谜。如今,在一项新的研究......