https://pubmed.ncbi.nlm.nih.gov/11897369/
https://www.ptglab.com/products/featured-products/proliferating-cells-brdu-and-ki-67-cellular-markers/
Is it better to use Ki67 or BrdU?
Even though BrdU and Ki67 are broadly used as proliferation markers and usually show similar expression patterns, they stain different groups of cells. BrdU labels cells during the S phase, whereas Ki67 labels cells in the G1, S, G2, and M phases (only Go cells should be negative for Ki67). However, using only one marker may yield only partial information, while using both will ensure and enhance the reliability of the obtained results (4).
How to explain different results while working with BrdU and Ki67 for cell proliferation assay.
BrdU is a good marker for conducting time-course studies and is expressed during DNA replication and repair. Ki67 marks cells that are NOT in the G0 phase. Ki67 is strictly expressed during all stages of cell proliferation from G1, S, G2, and mitosis and is considered to be a better marker for cells in growth fraction. The S phase is constant (+/- 8 hours), whereas the overall cell cycle time is typically 24 hours, but possibly even a few days. Ki67 may even stain 3x as many cells compared to BrdU.
これってG2アレストのときもKi67で染まるんだろうか。そういえばG0とG1の違いはという議論もある。
全体的にはBrdUポジは投与後から観察の間にDNA合成が起こっていた細胞。だから投与した頃にはDNA合成していても、観察時には細胞周期が止まっているかもしれないという見方もできる(そういう実験を組む人はあまりいないと思うけど)。
Ki67ポジは分裂して増殖するポテンシャルがある細胞を染めているとも言えるかもしれない。実際Ki67のほうがBrdUより多くの細胞が染まるらしい。
蛋白の発現が絶対に0になるのかという疑問もあるので、従来増殖してない細胞でも検出感度を上げると見えてくるかもしれないという不安があるがそういうテクニカルなことには詳しくないので経験のある方に書いてもらえればと思っている次第です。 |
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