MEF cell,第一代长的很好, 第二代就长的乱七八糟了,形态都不太规则,有大有小,还有多核的,有的都不像 fibroblast了 我完全照着protocol做的,medium里都加mercaptoethanol了 Current Protocols in Molecular Biology (2005) 28.1.1-28.1.8 UNIT 28.1 Preparation, Culture, and Immortalization of Mouse Embryonic Fibroblasts 有人有类似情况吗? MEF cell怎么能长得好?
If you culture MEF under 20% oxygen, then it is the best to use cells before passage 6 (please keep in mind that the best seeding density of MEF is about 5000/cm2.) If you culture the MEFs under 3-5% Oxygen, you can go up to 50 passages. Huge difference as you can see.
In your case, I think you might want to try different protocol. A good protocol should yield nice MEF culture from the wildtype embryo at least. The most important thing is to avoid overdigestion with trypsin, which will always leads to poor culture.
Good point. This is exactly right. LZ need to think about other experiments that can corroborate any findings from this paired immortalization experiment.
【在 h******y 的大作中提到】 : Good point. : This is exactly right. : LZ need to think about other experiments that can corroborate any findings : from this paired immortalization experiment. : : [发表自未名空间手机版 - m.mitbbs.com]
【在 h******y 的大作中提到】 : In your case, I think you might want to try different protocol. A good : protocol should yield nice MEF culture from the wildtype embryo at least. : The most important thing is to avoid overdigestion with trypsin, which will : always leads to poor culture. : : [发表自未名空间手机版 - m.mitbbs.com]
l*j
39 楼
我见过有人就用的wt MEF 然后转染shRNA做成KO,但是只有80%左右ko了。
findings
【在 h******y 的大作中提到】 : Good point. : This is exactly right. : LZ need to think about other experiments that can corroborate any findings : from this paired immortalization experiment. : : [发表自未名空间手机版 - m.mitbbs.com]
你说的比较温和是指什么? 来源于很多组织的人的fibroblast可以通过overexpress hTERT得到immortalization, 这是由于人的fibroblast在体外培养条件下的senescence多是由于端粒渐行缩短而导致 的(telomere-dependent replicative senescence)。与人的fibroblast不同,体外 培养中MEF的senescence并不是由于端粒缩短引起的,而是由于如前所述的过氧基团累积 oxidative stress induced DNA damage。研究表明senescence的MEF的端粒还很长,而 且MEF中有较高的mTERT表达,所以过表达mTERT并不能有效immortalize MEF。因为要抑 制p53和Rb通路,所以表达异源的SV40 T和HPV16 E6/E7都可以immortalize MEF。当然 这样得到的细胞株,由于这些病毒蛋白的过量表达,基因组并不稳定,长久培养会出现 嬗变。 3T3办法引起的自发immortalization实际上主要是由于自发的p53通路抑制(p53 loss or p19 loss)。或者你研究的基因/通路补偿了p53或者p19的缺失,所以很难得到 immortalized的细胞株? 3T3方法我自己没有用过,从文献里照抄一段供参考。 D. Immortalization by Serial Passage 1. Split MEFs 1:3 twice per week during the rapid growth phase of the culture (the first 6-10 passages). 2. As cells enter senescence, split 1:2 or merely replate (aim to keep cells near 100% confluency on the day of passaging). If the cultures are seeded too sparsely, this will decrease the immortalization frequency. 3. Between passages 10 and 20 (4 to 9 week in culture), immortalized lines will begin to overgrow the culture. These cells are smaller and spindle shaped, initially appearing as small nests of cells obvious on the day of passaging. These cells can be subcloned, but are used more frequently as pooled immortalized cells.
【在 h******y 的大作中提到】 : If you culture MEF under 20% oxygen, then it is the best to use cells before : passage 6 (please keep in mind that the best seeding density of MEF is : about 5000/cm2.) : If you culture the MEFs under 3-5% Oxygen, you can go up to 50 passages. : Huge difference as you can see. : : 3- : [发表自未名空间手机版 - m.mitbbs.com]