In-situ hybridization method using RecA protein and RecA protein having marker or ligand for use in said method

A kit including RecA protein having a detectable label or ligand, for use in practicing a method for detecting the presence of a double-stranded target nucleic acid sequence contained in fixed cells or cell structures, the method comprising the steps of:

• obtaining the fixed cells or cell structures by fixing cells or cell structures so as to allow a nucleic acid probe to enter;
• forming a probe/labeled RecA complex in which a single stranded probe and RecA protein having a detectable label or ligand are stably bound to each other, the single-stranded probe having a sequence complementary to the double-stranded target nucleic acid sequence;
• adding the probe/labeled RecA complex to the fixed cells or cell structures under conditions in which the probe/labeled RecA complex can come in contact with the double-stranded target nucleic acid sequence;
• allowing the probe/labeled RecA complex to react with the double-stranded target nucleic acid sequence so as to bind thereto under conditions where the double-stranded target nucleic acid sequence is not denatured;
• removing the unreacted part of the probe/labeled RecA complex that has not been bound to the double-stranded target nucleic acid sequence;
• and
• detecting the presence of the double-stranded target nucleic acid sequence by detecting the RecA protein having a detectable label or ligand included in the probe/labeled RecA complex bound to the double-stranded target nucleic acid.

A kit including probe/labeled RecA complex in which a probe and RecA protein having a detectable label or ligand are stably bound to each other, for use in practicing a method for detecting the presence of a double-stranded target nucleic acid sequence contained in fixed cells or cell structures, the method comprising the steps of:

• obtaining the fixed cells or cell structures by fixing cells or cell structures so as to allow a nucleic acid probe to enter;
• forming a probe/labeled RecA complex in which a single-stranded probe and RecA protein having a detectable label or ligand are stably bound to each other, the single-stranded probe having a sequence complementary to the double-stranded target nucleic acid sequence,
• adding the probe/labeled RecA complex to the fixed cells or cell structures under conditions in which the probe/labeled RecA complex can come in contact with the double stranded target nucleic acid sequence;
• allowing the probe/labeled RecA complex to react with the double-stranded target nucleic acid sequence so as to bind thereto under conditions where the double-stranded target nucleic acid sequence is not denatured;
• removing the unreacted part of the probe/labeled RecA complex that has not been bound to the double-stranded target nucleic acid sequence;
• and
• detecting the presence of the double-stranded target nucleic acid sequence by detecting the RecA protein having a detectable label or ligand included in the probe/labeled RecA complex bound to the double-stranded target nucleic acid.

A kit including RecA protein and an anti-RecA antibody comprising:

• RecA protein and an anti-RecA antibody both having a detectable label or ligand,
• wherein the kit is used for practicing a method for detecting the presence of a double-stranded target nucleic acid sequence contained in fixed cells or cell structures, the method comprising the steps of:
• obtaining the fixed cells or cell structures by fixing cells or cell structures so as to allow a nucleic acid probe to enter;
• forming a probe/labeled RecA complex in which a single-stranded probe and RecA protein having a detectable label or ligand are stably bound to each other, the single-stranded probe having a sequence complementary to the double-stranded target nucleic acid sequence;
• adding the probe/labeled RecA complex to the fixed cells or cell structures under conditions in which the probe/labeled RecA complex can come in contact with the double-stranded target nucleic acid sequence;
• allowing the probe/labeled RecA complex to react with the double-stranded target nucleic acid sequence so as to bind thereto under conditions where the double-stranded target nucleic acid sequence is not denatured;
• removing the unreacted part of the probe/labeled RecA complex that has not been bound to the double-stranded target nucleic acid sequence;
• and
• detecting the presence of the double-stranded target nucleic acid sequence by detecting the RecA protein having a detectable label or ligand included in the probe/labeled RecA complex bound to the double-stranded target nucleic acid,
• wherein the step of detecting the presence of the double-stranded target nucleic acid sequence is performed by further using an anti-RecA antibody having a detectable label or ligand.

A kit including a probe/labeled RecA complex comprising:

• RecA protein and an anti-RecA antibody both having a detectable label or ligand,
• wherein the RecA protein, having the detectable label or ligand, and a probe are stably bound to each other, for use in practicing a method for detecting the presence of a double-stranded target nucleic acid sequence contained in fixed cells or cell structures, the method comprising the steps of:
• obtaining the fixed cells or cell structures by fixing cells or cell structures so as to allow a nucleic acid probe to enter;
• forming a probe/labeled RecA complex in which a single-stranded probe and RecA protein having a detectable label or ligand are stably bound to each other, the single-stranded probe having a sequence complementary to the double-stranded target nucleic acid sequence;
• adding the probe/labeled RecA complex to the fixed cells or cell structures under conditions in which the probe/labeled RecA complex can come in contact with the double-stranded target nucleic acid sequence;
• allowing the probe/labeled RecA complex to react with the double-stranded target nucleic acid sequence so as to bind thereto under conditions where the double-stranded target nucleic acid sequence is not denatured;
• removing the unreacted part of the probe/labeled RecA complex that has not been bound to the double-stranded target nucleic acid sequence;
• and
• detecting the presence of the double-stranded target nucleic acid sequence by detecting the RecA protein having a detectable label or ligand included in the probe/labeled RecA complex bound to the double-stranded target nucleic acid,
• wherein the step of detecting the presence of the double-stranded target nucleic acid sequence is performed by further using anti-RecA antibody having a detectable label or ligand.