Evaluation of Fluorescent Analogs of Deoxycytidine for Monitoring DNA Transitions from Duplex to Functional Structures

Table 2

Fluorescence lifetimes of PdC and tC° in single- and double-strand DNA. The 𝜏₁ and 𝜏₂ are obtained by fitting a double exponential decay curve to the data, and 𝑓₁ and 𝑓₂ are fraction of fluorescence corresponding to lifetimes 𝜏₁ and 𝜏₂, respectively. The Χ² indicate the measure of error in the fit. The value ⟨𝜏⟩ is average lifetime calculated by ∑𝑓_𝑖𝜏²_𝑖/∑𝑓_𝑖𝜏_𝑖.

Oligo	𝜏1 (ns)	𝑓1	𝜏2 (ns)	𝑓2	Χ^2	⟨𝜏⟩ (ns)
ss tC°	5.3	0.9	1.7	0.1	2.0	5.1
ds tC°	5.1	0.8	1.8	0.2	1.5	4.8
ss PdC	5.2	0.7	0.7	0.3	1.9	5.1
ds PdC	3.3	0.6	0.1	0.3	1.4	3.2