What is the test called for a subcutaneous tick? - briefly
The diagnostic method is a polymerase‑chain‑reaction (PCR) assay applied to the tick or to the patient’s blood to detect tick‑borne pathogens. It identifies DNA of organisms such as Borrelia, Anaplasma, or Ehrlichia.
What is the test called for a subcutaneous tick? - in detail
The diagnostic procedure employed to identify a tick that has embedded beneath the skin is a molecular assay, commonly referred to as a PCR‑based tick identification test. This method amplifies DNA extracted from the lesion or surrounding tissue, allowing precise species determination.
The assay proceeds through several distinct phases:
- Specimen acquisition – a small biopsy or fine‑needle aspirate is taken from the area surrounding the tick’s mouthparts. The sample must be placed in a sterile transport medium and kept at low temperature until processing.
- DNA extraction – specialized kits isolate nucleic acids from the collected material, removing inhibitors that could interfere with amplification.
- Polymerase chain reaction – primers targeting conserved regions of mitochondrial 16S rRNA or cytochrome oxidase I genes are added. The thermal cycler amplifies any tick DNA present, generating enough product for downstream analysis.
- Sequencing or melt‑curve analysis – the amplified fragments are either sequenced and compared against reference databases, or subjected to high‑resolution melt analysis to differentiate species based on characteristic melting temperatures.
- Result interpretation – a positive amplification indicates the presence of tick tissue; species identification guides clinical management, as different ticks transmit distinct pathogens.
Key advantages of this approach include high sensitivity, the ability to detect partially degraded specimens, and rapid turnaround (typically 24–48 hours). Limitations involve the need for specialized laboratory equipment, potential contamination leading to false positives, and the fact that the test does not directly assess pathogen transmission. Complementary serologic or PCR tests for specific tick‑borne diseases (e.g., Borrelia, Anaplasma) are often ordered once the tick species has been confirmed.