Table I.

RL-SAGE modifications compared with LongSAGE and conventional SAGE methods

	Library Features	RL-SAGE	LongSAGE (Saha et al., 2002)	Conventional SAGE (Velculescu et al., 1995)
1.	mRNA quantity	50 ng	2 μg	5 μg
2.	Ligation of cDNAs to adapters	Overnight	Not reported	2 h
3.	cDNA digestion with N/aIII	2.5 h	1 h	1 h
4.	Ditag ligation	Overnight	2.5 h	overnight
5.	Number of PCRs	20 PCRs	Not reported	300 PCRs
6.	Ditags (136 bp) band purification	Individual PCR resolved	Not reported	PCR products pooled, precipitated, and resolved
7.	Purification of ditags (40 bp)	16% (w/v) Polyacrylamide gel	Not reported	12% (w/v) Polyacrylamide gel
8.	Linkers removed	M-280 streptavidin Dynabeads	Not reported	Not reported
9.	Digestion of concatemers	10 units of N/aIII (37°C, 1 min)	Not reported	Not reported
10.	Purification of concatemers	6% (w/v) Polyacrylamide gel	Not reported	8% (w/v) Polyacrylamide gel
11.	Clones screened	Randomly picked	Not reported	Colony PCR screened
12.	Average insert size	1.00 kb	Not reported	300—500 bp
13.	Total tags per concatemer	50 tags (21 bp)	Not reported	22 tags (14 bp)