Light absorption by rhodopsin→activation of a cGMP PDE → hydrolyzes cGMP to 5′-GMP→ cGMP levels  drop →channel close →membrane hyperpolarization→reduction in NT release→transmitted to brain

TLS Online TPP Program

#Id: 2629

#Unit 13. Methods in Biology

End-labelling of a gene probe at the 5′ end with alkaline phosphatase and polynucleotide kinase. 

TLS Online TPP Program

#Id: 2630

#Unit 13. Methods in Biology

End-labelling of a gene probe at the 3′ end using terminal transferase. Note that the addition of a labeled dNTP at the 3′ end alters the sequence of the gene probe.

TLS Online TPP Program

#Id: 2631

#Unit 13. Methods in Biology

S1 mapping is used to locate the 5’- or 3’-ends of RNAs and to quantify the amount of a given RNA in cells at a given time. 

TLS Online TPP Program

#Id: 2632

#Unit 13. Methods in Biology

The principle behind the S1 mapping method is to label a single stranded DNA probe that can hybridize only to the transcript of interest. 

TLS Online TPP Program

#Id: 2633

#Unit 13. Methods in Biology

The probe must span the sequence where the transcript starts or ends. After hybridizing the probe to the transcript, one applies S1 nuclease, which degrades only single-stranded DNA and RNA. 

TLS Online TPP Program

#Id: 2634

#Unit 13. Methods in Biology

The probe must span the sequence where the transcript starts or ends. After hybridizing the probe to the transcript, one applies S1 nuclease, which degrades only single-stranded DNA and RNA.