quantifying viral load
Oct 5, 2000
Is viral load determined before or after PCR amplification? The reason I ask is that I see "50 perMl" given as the number at which the virus is undetectable, and that would mean that before PCR virtually everyone who is HIV positive is "undetectable".
Response from Dr. Holodniy
A 50 copy viral load is what is there before PCR. An internal standard of known copy number is added to each patients sample of unknown copy number. Based on the signal obtained in a PCR assay for the known standard, the patient copy number is calculated. After PCR there are literally billions of copies of HIV floating around. We could never detect 50 copies without the amplification that PCR affords. So a viral load of 50 copies is a back extrapolation to the starting material.
Get Email Notifications When This Forum Updates or Subscribe With RSS
This forum is designed for educational purposes only, and experts are not rendering medical, mental health, legal or other professional advice or services. If you have or suspect you may have a medical, mental health, legal or other problem that requires advice, consult your own caregiver, attorney or other qualified professional.
Experts appearing on this page are independent and are solely responsible for editing and fact-checking their material. Neither TheBody.com nor any advertiser is the publisher or speaker of posted visitors' questions or the experts' material.