Dipstick, poly

Dipsticks (poly-dT coated) Store at room temperature in a dessicated container. 

When the 15-min incubation is complete, remove the cover from the tubes and add a plastic poly-dT coated dipstick to each tube. Incubate the dipsticks m the tubes for 1 h at 65 C. 

A dipstick probe can be used to identify organisms in clinical or environmental specimens. It consists of adding a capture probe (containing a sequence of poly-dA or -dT bases that identifies it as a capture probe) coupled to dioxygenin as a reporter. Following destruction of unhybridized probe material, a dipstick that can hybridize with the capture probe base sequence is added. After all steps are completed, the presence of the capture probe is positive for the organism of interest. The theoretical sensitivity of a probe is < 1 pg of nucleic acid or 10 cells. However, by use of polymerase chain reaction (PCR), the DNA of a single cell can be amplified several millionfold. 

---