(a) Single growth factors used in this work and groups containing all of the growth factors belonged to the same type

Group 1: containing amino acids from 2–24	2: Asp	3: Cys	4: Ile
5: Gly	6: Glu	7: Val	8: Ser
9: Ala	10: His	11: Tyr	12: Phe
13: Met	14: Thr	15: Met	16: Trp
17: Pro	18: Leu	19: Lys	20: cystine
21: Arg	22: Asp	23: Asn	24: Gln
Group 25: containing vitamins from 26 to 35	26: vitamin H	27: vitamin C	28: vitamin B6
29: vitamin B3	30: vitamin B5	31: vitamin B4	32: vitamin B2
33: vitamin B9	34: vitamin B12	35: vitamin B1
Group 36: containing dNTPs from 37 to 43	37: dATP	38: dGTP	39: dTTp
40: dCTP	41: dUTP	42: xanthine	43: hypoxanthine