Methods for detecting DNA originating from different individuals

Abstract

In a first aspect, the present invention features methods for differentiating DNA species originating from different individuals in a biological sample. These methods may be used to differentiate or detect fetal DNA in a maternal sample or to differentiate DNA of an organ donor from DNA of an organ recipient. In preferred embodiments, the DNA species are differentiated by observing epigenetic differences in the DNA species such as differences in DNA methylation. In a second aspect, the present invention features methods of detecting genetic abnormalities in a fetus by detecting fetal DNA in a biological sample obtained from a mother. In a third aspect, the present invention features methods for differentiating DNA species originating from an organ donor from those of an organ recipient. In a fourth aspect, the present invention features kits for differentiating DNA species originating from different individuals in a biological sample.

1 - 39 . (canceled)  
     
     
         40 . A kit for differentiating DNA species originating from cells of different individuals, wherein the DNA species are in a biological sample obtained from one of the individuals, the kit comprising: 
 (i) a reagent for extracting the DNA species from the biological sample; and    (ii) a reagent for detecting a methylation difference between the DNA species;    wherein the detection of the methylation difference indicates DNA species from different individuals.    
     
     
         41 . The kit according to  claim 40 , wherein the reagent for detecting the methylation difference comprises sodium bisulfite.  
     
     
         42 . The kit according to  claim 40 , further comprising: 
 (iii) a reagent for amplifying the DNA species.    
     
     
         43 . The kit according to  claim 42 , wherein the reagent for amplifying the DNA species is a reagent for performing a polymerase chain reaction to generate a PCR product.  
     
     
         44 . The kit according to  claim 42 , wherein the reagent for amplifying the DNA species comprises a reagent for performing a methylation-specific polymerase chain reaction.  
     
     
         45 . The kit according to  claim 42 , wherein the reagent for amplifying the DNA species comprises PCR primers distinguishing the sequence difference between methylated and unmethylated DNA following bisulfite conversion.  
     
     
         46 . The kit according to  claim 42 , wherein the reagent for amplifying the DNA species comprises a set of PCR primers designed for a methylated DNA sequence.  
     
     
         47 . The kit according to  claim 42 , wherein the reagent for amplifying the DNA species comprises a set of PCR primers designed for an unmethylated DNA sequence.  
     
     
         48 . The kit according to  claim 46 , wherein the methylated DNA sequence is that of an androgen receptor gene or IGF2-H 19 gene.  
     
     
         49 . The kit according to  claim 47 , wherein the unmethylated DNA sequence is that of an androgen receptor gene or IGF2-H 19  gene.  
     
     
         50 . The kit according to  claim 43 , further comprising: 
 (iv) a reagent for sequencing the PCR product.    
     
     
         51 . The kit according to  claim 43 , further comprising: 
 (iv) a reagent for purifying the PCR product.    
     
     
         52 . The kit according to  claim 43 , further comprising: 
 (iv) a reagent for detecting the presence of the PCR product.    
     
     
         53 . The kit according to  claim 52 , wherein the reagent for detecting the presence of the PCR product is a gel.  
     
     
         54 . The kit according to  claim 40 , further comprising: 
 (iii) a reagent for performing primer extension.    
     
     
         55 . The kit according to  claim 40 , further comprising: 
 (iii) a reagent for performing real-time PCR.    
     
     
         56 . The kit according to  claim 40 , further comprising: 
 (iii) a marker.    
     
     
         57 . The kit according to  claim 40 , wherein the biological sample is a fluid or cellular sample or a mixture thereof.  
     
     
         58 . The kit according to  claim 40 , wherein the biological sample is plasma, serum, blood or amniotic fluid.  
     
     
         59 . The kit according to  claim 58 , further comprising: 
 (iii) EDTA;    wherein the EDTA is added to the biological sample.    
     
     
         60 . The kit according to  claim 40 , wherein the cells of different individuals comprise cells of a transplantation recipient and cells from an organ donor, wherein the DNA species are in a biological sample obtained from the transplantation recipient and wherein the detection of the methylation difference allows the differentiation of DNA species derived from the transplantation recipient from those derived from the organ donor.  
     
     
         61 . A kit for detecting a methylation difference between DNA species originating from cells of a pregnant female and an unborn fetus, wherein the DNA species are in a biological sample obtained from either the pregnant female or unborn fetus, the kit comprising: 
 (i) a reagent for extracting the DNA species from the biological sample; and    (ii) a reagent for detecting a methylation difference between the DNA species;    wherein the detection of the methylation difference is associated with a fetal or maternal disorder.    
     
     
         62 . The kit according to  claim 61 , wherein the disorder is preeclampsia, a chromosomal aneuploidy, trisomy 21 (Down syndrome), Prader Willi Syndrome or Angelman Syndrome.