Question

How and why are positive and negative controls used for the PCR?

Answer 1

A positive control is one that you hope to work under the conditions given. The positive control will test your master mix, MgCl2 sums, primer annealing temperature, and extension times. On the off chance that your positive control does not work, those results show that something isn't right with your annealing or extension times or temperatures, or something isn't right with your MgCl2 or master mix set up. In the event that your positive control does work and your test tests don't, at that point there could be something different going on, for example, insufficient or a lot of templates. I will frequently utilize a plasmid with the coveted succession I need to enhance my positive control (normally around 500 pg as a sum).

A negative control for PCR is one which ought not to give you amplicons, regularly the negative control will contain no template or will have either primer. Setting up two negative controls, each containing just the forward or reverse primer, ought not to give visible amplicons. In this way, any visible bands may be a result of contamination or different opposing binding locales for the composed primers.

A negative control is one you anticipate that not will work under the conditions. A positive control is one you hope to work and to give you the normal result.