Biotin-labeled DNA probe in a PCR-based assay increases detection sensitivity for the equine hemoparasite Babesia caballi.

The researchers developed a more sensitive method for detecting the horse parasite Babesia caballi using a DNA probe in a PCR-based assay.

Background

• Babesia caballi is a hemoparasite or a blood parasite that affects equines, commonly horses. Detecting this parasite is crucial for disease management and prevention.
• Polymerase Chain Reaction (PCR) is a common method of amplifying specific DNA sequences for detection. However, in this study, the researchers developed a PCR-based assay that increases the detection sensitivity for B. caballi.

Methodology

• The researchers selected a DNA probe from B. caballi, labeled as Bc1, through antibody screening of a genomic library.
• The specific target for this probe was the genomic DNA of B. caballi. Ensuring specificity of the probe to this DNA sequence was a key step in the development process.
• Primers derived from the nucleotide sequence of the probe were used to develop a PCR-based assay for B. caballi DNA.
• In a laboratory setup, with as little as 500 femtogram (fg) of B. caballi DNA as the template, they could achieve an amplified PCR product of 1.6 kilobases (kb).

Findings

• The probe was labeled with biotin, a molecule commonly used in molecular biology for its ability to bind to other substances and facilitate detection.
• For detection of amplicons or amplified DNA, the biotin-labeled probe was hybridized via Southern blot technique. This subjected the amplicons to denaturation, transfer, and subsequent binding with the probe.
• The result was a 1000-fold increase in sensitivity of detection when compared to conventional PCR-based assays.
• This method allows for more accurate and early detection of the B. caballi parasite in blood samples.