(1) There is a problem with the reagent, resulting in no DNA in the sample.
(2) The electrophoresis time is too long, or the electrophoresis direction is reversed, resulting in no DNA in your gel.
(3) There is no fluorescent dye (such as EB, SyBR Gold, etc.) added to the gel, so even if there is DNA in the gel, it cannot develop color.
(4) Gel scanner imaging question.
1. First pick out the impurities from the purchased peppers and remove the unclean ones. Generally, the pepper particles bought back are drie