Increase lysis at 75 °C to 15 minutes to improve release of DNA
Dilute DNA extract with TE or 10 mM Tris-HCl, pH 8.0-8.5 before PCR
Use at least 40 PCR cycles
Increase extension time to 20 or 30 seconds per cycle
Decrease annealing temperature by 2 °C–5 °C, but do not go lower than 50 °C
Ensure that tissue was completely immersed in the buffer during extraction