Materials:

a. Prepare 20 pieces of hair

b. Prepare Hair Follicle Lysis buffer with 1×PCR buffer (50mmol·L^-1 KCl, 10mmol·L^-1 Tris·Cl, 0.01% gelatin) Add MgCl2 to 2m mol·L^-1, Proteinase K, 20mg·L^-1

Methods for extracting DNA from hair

1. Wash the hair once with 70% ethanol. Then rinse the hair twice with distilled water.

2. Place 1 to 4 pieces of hair in each of 5 200μL PCR tubes. Place the hair follicles at the bottom of the PCR tubes and use clean scissors to cut off the part of the hair that is higher than the tube. Set up a blank control tube.

3. Add 15 μL of prepared hair follicle lysis buffer to each tube.

4. Set a single cycle program on the PCR instrument: 65℃ 30min, 95℃ 15min, 4℃ 10min. Put the PCR tube from the previous step into the preheated PCR instrument and run the program.

5. After the program is completed, the PCR tube is centrifuged instantly, 2 μL is taken as the PCR template, and the remaining part is placed at -20℃