Compositions and methods for labeling of nucleic acid molecules

Abstract

The present invention is generally related to compositions, kits and methods for labeling nucleic acid molecules using reverse transcriptases, preferably multi-subunit reverse transcriptases such as ASLV reverse transcriptases. Specifically, the invention relates to methods, kits and compositions for to fluorescently labeling nucleic acid molecules during nucleic acid synthesis. The labeled nucleic acid molecules produced in accordance with the invention are particularly suited as labeled probes for nucleic acid detection and diagnostics.

1 . A composition for use in labeling one or more nucleic acid molecules, said composition comprising one or more enzymes having reverse transcriptase activity, wherein said enzymes are multi-subunit enzymes. 
   
   
       2 . The composition of  claim 1 , wherein said enzymes are heterodimers. 
   
   
       3 . The composition of  claim 1 , wherein said enzymes are selected from the group consisting of ASLV reverse transcriptases. 
   
   
       4 . The composition of  claim 1 , wherein said enzymes are reduced or substantially reduced in RNase H activity. 
   
   
       5 . The composition of  claim 1 , wherein said enzymes are selected from the group consisting of RSV reverse transcriptase, AMV reverse transcriptase, RAV reverse transcriptase, MAV reverse transcriptase and HIV reverse transcriptase, and derivatives, variants, fragments or mutants thereof. 
   
   
       6 . The composition of  claim 1 , wherein said composition further comprises one or more fluorescently labeled nucleotides. 
   
   
       7 . The composition of  claim 6 , wherein said nucleotides are labeled with a fluorescent molecule or marker selected from the group consisting of rhodamine, fluoroescein, Cy3, and Cy5. 
   
   
       8 . The composition of  claim 1 , wherein said composition further comprises one or more DNA polymerases, and mutants, fragments, variants and derivatives thereof. 
   
   
       9 . The composition of  claim 1 , wherein said composition further comprises a reverse transcription buffer and/or a nucleic acid template. 
   
   
       10 . A method for reverse transcription of one or more nucleic acid molecules comprising
 (a) mixing one or more nucleic acid templates with one or more enzymes having reverse transcriptase activity, wherein said enzymes are multi-subunit enzymes; and   (b) incubating said mixture under conditions sufficient to make one or more first nucleic acid molecules complementary to all or a portion of said one or more templates, wherein at least one of said first nucleic acid molecules is detectably labeled.   
   
   
       11 . The method of  claim 10 , wherein said nucleic acid template is a messenger RNA (mRNA) molecule or a population of mRNA molecules. 
   
   
       12 . The method of  claim 10 , said method further comprising incubating said one or more first nucleic acid molecules under conditions sufficient to make one or more second nucleic acid molecules complementary to all or a portion of said one or more first nucleic acid molecules. 
   
   
       13 . The method of  claim 10 , wherein said enzymes are selected from the group consisting of ASLV reverse transcriptases. 
   
   
       14 . The method of  claim 10 , wherein said enzymes are selected from the group consisting of RSV RT, AMV RT, ThermoScript™ and ThermoScript™ II. 
   
   
       15 . The method of  claim 10 , wherein said detectable label is a fluorescent label. 
   
   
       16 . The method of  claim 10 , wherein said fluorescent label is selected from the group consisting of fluorescein, rhodamine, Cy3 and Cy5. 
   
   
       17 . The method of  claim 10 , wherein said detectably labeled first nucleic acid molecules comprise one or more fluorescently labeled nucleotides. 
   
   
       18 . The method of  claim 10 , wherein said detectable labels are the same or different. 
   
   
       19 . The method of  claim 18 , wherein said detectable labels are fluorescent labels. 
   
   
       20 . A labeled nucleic acid molecules prepared according to the method of  claim 10 . 
   
   
       21 . A kit for use in labeling one or more nucleic acid molecules, said kit comprising one or more enzymes having reverse transcriptase activity, wherein said enzymes are multi-subunit enzymes. 
   
   
       22 . The kit of  claim 21 , said kit further comprising one or more components selected from the group consisting of one or more nucleotides, one or more DNA polymerases, a suitable buffer, and one or more primers. 
   
   
       23 . The kit of  claim 22 , wherein at least one or said nucleotides are fluorescent nucleotides.