Polymerase chain reaction-based detection of Trypanosoma cruzi DNA in serum.

DNAs prepared from chagasic patients' sera were amplified by the polymerase chain reaction using oligonucleotide primers which anneal specifically to a highly repetitive sequence of Trypanosoma cruzi nuclear DNA. Samples from both acutely and chronically infected patients yielded positive results by this method. No significant difference was observed when either whole blood or serum samples of the patients were used. These results indicate that serum instead of whole-blood samples could be used for polymerase chain reaction-based detection of T. cruzi in field studies without the need of applying any special chemical treatment to the specimens. This would represent a considerable advantage due to the easier handling and transportation of serum as compared with whole-blood samples, especially in tropical climates.