796855 tn?1237431399

Roche Cobas Ampliprep Test

Hi folks! I haven't been on here in quite a while.  I finally got insurance and my doc had me take the Roche COBAS Ampliprep/COBAS Taqman HCV Test.  I got the results from the lab on Friday.  

The results are Hep C RNA not detected.

I read as much as I could on this forum before posting but either still don't quite understand and/or just need reassurance.  

I was told in 1996 i have anti-bodies and again throughout the years.

I have been convinced for years that I have Hep C.

the test says it has an analytical measurement range of 43-69,000,000 IU/mL  and then in parentheses it says (1.63-7.84 logIU/ml)

next to where it says my results "not" detected" it has a column for "reference range" and nothing is typed there...it is blank.

Any ideas what this means?

Since I got the lab results in the mail Friday I haven't been able to talk to my doctor and as you can imagine i am at my wit's end trying to understand iff this means what i hope it means and if the lack of a reference range is normal.

Thank you for reading and always your responses are appreciated!

6 Responses
796855 tn?1237431399
I found a post somewhere on this site that lead me o a GREAT place that really  clarified the tests...and types of tests...

I had a test called a real time polymerase chain reaction (RTPCR) done by Roche COBAS Ampliprep/ COBAS Taqman  HCV Test (to be specific).

I found out that...

"A critically important advance in molecular diagnostics has been the adaptation of real-time PCR methods to quantify HCV RNA. Using TaqMan technology, real-time PCR yields quantitative results with comparable sensitivity to qualitative tests. In addition, real-time PCR can accurately quantify HCV RNA levels over a linear range exceeding 6 logs (ie, 10 IU/mL to 100 million IU/mL) for purposes of therapeutic monitoring (Table 2).36 Therefore, a single test result serves the purpose of both quantitative and qualitative HCV NATs. The assay is faster and more cost-effective than the other techniques and has already replaced other NAT testing platforms at many institutions. However, real-time PCR assays are presently available only as in-house tests."

I am gathering from this paragraph that the test I was given is an advanced test that serves as both qualitative and quantitative in one single test....

I feel from reading this that i really could be HCV free...for real...and have believed for years to be infected....I want to thank

"willing"  for the original post for that link...it helped answer a lot of questions...thank you and i hope by re-posting the above info i have helped someone else out...here is the link to the article:


and if anyone needs clarification as to qualitative vs. quantitative tests this could be helpful...and if you want to know what test you should get I would suggest (from reading this info...) to get this REAL-TIME PCR test...

thank you again...i wish everyone here the best...truly!!!
i am keeping my fingers crossed that this means i really don't have it and somehow this old body of mine fought of that virus!

take care
796855 tn?1237431399
i keep addressing my own post but i want to tag this so others can find the information too :)

i found a another great site about the differences between qualitative and quantitative tests...and it includes the REAL Time PCR tests like the one i had done



if you need some answers pleas read these...if you are curious about what test you had and what it all means...please read these links

796855 tn?1237431399
Please note that effective mid-August 2005, the laboratory method used for measuring Hepatitis C quantitative viral loads in the OHSU Molecular Diagnostic Center will be changing (test numbers 102-8804 and 102-8814). In particular, the new HCV viral load test will be utilizing a more sensitive real-time quantitative PCR method that offers several technical and clinical advantages including:
1) Lower detection limit down to 25 international units (IU) per mL of serum
(compared to 600 IU/mL for the old PCR-ELISA quantitative method)
2) Linear reportable range of 6 logs (25 to 25,000,000 IU/mL)
(compared to only 3.1 logs for the old PCR-ELISA method; 12,000 – 17,000,000 IU/mL)
3) Excellent assay precision (reproducibility) as measured by a coefficient of variation (standard deviation divided by mean) of 2.1%
4) Internal control (synthetic template) added to each sample to ensure accurate viral load quantitation and absence of sample-specific PCR inhibitors
In a direct comparison of the quantitative results obtained with the two different methods (n=46), we have found that the HCV viral load values from the new real-time PCR method are, on average, approximately 2-fold (0.3 logs) LOWER than the viral loads determined with the PCR-ELISA method that has been in use in our lab for many years. Please take this assay-dependent bias into consideration when interpreting new viral load values derived from the real-time PCR assay after mid-August 2005.
Because of the relatively poor low-level sensitivity for the old PCR-ELISA method for HCV viral loads (600 IU/mL), a more sensitive qualitative HCV PCR assay had been available with a low-level detection limit of 100 IU/mL of serum. Because of the even better low-level sensitivity of the new real-time quantitative PCR assay for HCV (down to 25 IU/mL), there is no further need for the lab to continue to offer the less sensitive qualitative HCV PCR assay. Effective mid-August 2005, the qualitative HCV PCR assay (test #102-8815) will therefore no longer be available and all requests for the “qualitative” HCV PCR test will instead, receive a quantitative real-time PCR viral load determination (test #102-8804).
Should you have any questions about this change in assay methodology, please call the Molecular Diagnostic Center at 503-494-5400.
Hep C
Avatar universal
Hi, I'm in the same situation.  I've received two indeterminate antibody tests and had the same RNA test done recently.  It is not detected and there is a blank Reference Range, too.  It would be nice to know soon any certainty......
Avatar universal
The NAT result has a flag saying Q_QS INVALID. What does it mean? The manual says Internal Control is invalid. I ran the test again this time Target not Detected. 2 Cobas NAT analyzer I'm using. Everyday there is one result giving this flag but on one machine only. Some problem with the machine or the test?
Avatar universal
The bottom line is, the test could not detect measurable virus.

In all liklihood, you do not have a chronic Hep C infection. You may have been exposed at one time, but approximately 20% of patients are able to rid the body of the virus and thats the end of it.

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