Process for amplifying nucleic acids

Abstract

The present invention relates to a process for synthesizing or amplifying efficiently a nucleic acid comprising a target nucleic acid sequence. In the process according to the present invention, a primer comprising in its 3′-end portion a sequence (Ac′) which hybridizes a sequence (A) in the 3′-end portion of the target nucleic acid sequence, and in the 5′-side of said sequence (Ac′) a sequence (B′) which hybridizes the complementary sequence (Bc) of a sequence (B) positioned in the 5′-side of said sequence (A) on the target nucleic acid sequence, wherein {X−(Y−Y′)}/X is in the range of −1.00 to 1.00, in which X denotes the number of bases in said sequence (Ac′), Y denotes the number of bases in the region flanked by said sequences (A) and (B) in the target nucleic acid sequence, and Y′ denotes the number of bases in an intervening sequence between said sequences (Ac′) and (B′) (Y′ may be zero).

1 - 17 . (canceled) 
     
     
         18 . A primer for synthesizing a nucleic acid complementary to a target nucleic acid sequence in a template nucleic acid, comprising in its 3′-end portion a sequence (Ac′) which hybridizes a sequence (A) in the 3′-end portion of the target nucleic acid sequence, and in the 5′-side of said sequence (Ac′) a sequence (B′) which hybridizes the complementary sequence (Bc) of a sequence (B) positioned in the 5′-side of said sequence (A) on the target nucleic acid sequence, wherein
 in the absence of an intervening sequence between said sequences (Ac′) and (B′), (X−Y)/X is in the range of −1.00 to 1.00, in which X denotes the number of bases in said sequence (Ac′), and Y denotes the number of bases in the region flanked by said sequences (A) and (B) on the target nucleic acid sequence, and 
 in the presence of an intervening sequence between said sequences (Ac′) and (B′), {X−(Y−Y′)}/X is in the range of −1.00 to 1.00, in which X and Y have the same meanings as above, and Y′ denotes the number of bases in said intervening sequence. 
 
     
     
         19 . A kit for synthesizing a nucleic acid complementary to a target nucleic acid sequence in a template nucleic acid, comprising the primer according to  claim 18 . 
     
     
         20 . A primer set for amplifying a target nucleic acid sequence in a double-stranded template nucleic acid, which comprises:
 (a) a first primer comprising in its 3′-end portion a sequence (Ac′) which hybridizes a sequence (A) in the 3′-end portion of the target nucleic acid sequence in the first strand of the double-stranded template nucleic acid, and in the 5′-side of said sequence (Ac′) a sequence (B′) which hybridizes the complementary sequence (Bc) of a sequence (B) positioned in the 5′-side of said sequence (A) on said target nucleic acid sequence, wherein
 in the absence of an intervening sequence between said sequences (Ac′) and (B′), (X−Y)/X is in the range of −1.00 to 1.00, in which X denotes the number of bases in said sequence (Ac′), and Y denotes the number of bases in the region flanked by said sequences (A) and (B) on the target nucleic acid sequence, and 
 in the presence of an intervening sequence between said sequences (Ac′) and (B′), {X−(Y−Y′)}/X is in the range of −1.00 to 1.00, in which X and Y have the same meanings as above, and Y′ denotes the number of bases in said intervening sequence; and (b) a second primer comprising in its 3′-end portion a sequence (Cc′) which hybridizes a sequence (C) in the 3′-end portion of the target nucleic acid sequence in the second strand of the double-stranded template nucleic acid, and in the 5′-side of said sequence (Cc′) a sequence (D′) which hybridizes the complementary sequence (Dc) of a sequence (D) positioned in the 5′-side of said sequence (C) on said target nucleic acid sequence, wherein 
 in the absence of an intervening sequence between said sequences (Cc′) and (D′), (X−Y)/X is in the range of −1.00 to 1.00, in which X denotes the number of bases in said sequence (Cc′), and Y denotes the number of bases in the region flanked by said sequences (C) and (D) on the target nucleic acid sequence, and 
 in the presence of an intervening sequence between said sequences (Cc′) and (D′), {X−(Y−Y′)}/X is in the range of −1.00 to 1.00, in which X and Y have the same meanings as above, and Y′ denotes the number of bases in said intervening sequence. 
   
     
     
         21 . A kit for amplifying a target nucleic acid sequence in a double-stranded template nucleic acid, comprising the primer set according to  claim 20 .