The phosphorylation pattern on the CTD is dynamic during the elongation process, catalyzed and controlled by multiple protein kinases, including P-TEFb, and phosphatases. Most oft the basal transcription factors are released from the promoter at this stage.

TLS Online TPP Program

#Id: 4596

#Unit 13. Methods in Biology

Diphenyltetrazolium bromide, a yellow tetrazole is reduced by metabolically active cells to form insoluble, purple formazan dye crystals detected at 570nm

TLS Online TPP Program

#Id: 4597

#Unit 13. Methods in Biology

The more metabolically active cells that are present in the culture, the more formazan will be generated, and so this assay provides a readout of the number of live cells as a function of time.

TLS Online TPP Program

#Id: 4598

#Unit 13. Methods in Biology

 The MTT assay can measure cell proliferation or cell death.

TLS Online TPP Program

#Id: 4599

#Unit 13. Methods in Biology

bromodeoxyuridine (BrdU) is rapidly phosphorylated and incorporated in its place into newly synthesized DNA hence BrdU is used to detect replicating cells.

TLS Online TPP Program

#Id: 4600

#Unit 13. Methods in Biology

BrdU can CAUSE light induced cell death

TLS Online TPP Program

#Id: 4601

#Unit 13. Methods in Biology

If cells that have incorporated a high level of BrdU are exposed to light, they will photolyse; this has been used to selectively kill newly dividing cells.