Table 1.

Spectral properties of the nucleosides and their bases at pH 13.

	Compound	${\mathsf{\lambda }}_{\mathbf{max}}$ Nucleoside [nm]	${\mathsf{\lambda }}_{\mathbf{max}}$ Base [nm]	Isosbestic Point for Base Cleavage [nm]	Upper Limit of Range for Fitting [nm]
Pyrimidines	Uridine	262	281	271	310
	2’-Deoxyuridine	262		272	310
	5-Methyluridine +	267	290	277	320
	2’-Deoxythymidine $	266		278	320
	5-Fluorouridine *	269	281	282	325
	2’-Deoxy-5-fluorouridine *	268		280	325
	5-Bromouridine	276	290	283	330
	2’-Deoxy-5-bromouridine	275		282	330
	5-Iodouridine *	281	291	283	340
	2’-Deoxy-5-Iodouridine *	279		282	340
	5-Ethynyluridine *	285	298	262, 288	340
	2’-Deoxy-5-ethynyluridine *	284		262, 288	340
	Cytidine #	271	281	271	310
	2’-Deoxycytidine #	271		271	310
Purines	Adenosine	259	268	267	310
	2’-Deoxyadenosine	259		267	310
	Guanosine	264	273	279	310
	2’-Deoxyguanosine	264		279	310
	Inosine	252	262	263	320
	2’-Deoxyinosine	252		263	320

* pH 13.3 (equal to 200 mM NaOH), ^# pH 13.7 (equal to 500 mM NaOH), ⁺ equivalent to 2’-hydroxythymidine, ^$ equivalent to 2’-deoxy-5-methyluridine and commonly referred to as thymidine