I have to do standard quantification for PCV2 virus in serum samples.

I did my test of efficiency with my plasmid (E=100%).

My field samples after extraction are very poor in DNA quality and very contaminated with salt. Because of this I couldn't do my test of efficiency with field samples.

My question: Do I need to do a test of efficiency (5 points) with my samples (a positive sample)?

Test of Efficiency with a positive sample is recommended or required for standard quantification?(absolute)

If I not do the Test Of Efficiency with a positive sample, can I simply compare the samples Cts with my curve?