Clongen Labs currently offer a test for the presence of XMRV by Real Time PCR.


Daughters High School Graduation
Upstate SC, USA
This is interesting! The homepage of the site gives the indication that it was just added as an available test! Thanks ChuckG


Senior Member
I can't see any difference between this test and the one that they advertised last year though?


Daughters High School Graduation
Upstate SC, USA
I can't see any difference between this test and the one that they advertised last year though?
That's kind of what I was thinking that this test was marketed sometime back. I'm vaquely remembering that this company was associated with one of the "negative" xmrv studies and had pulled the test.


Phoenix Rising Founder
Arizona in winter & W. North America otherwise
Real time - doesn't that measure viral load? - I think it does.....

Real Time PCR vs Traditional PCR vs Digital PCR

Real-Time PCR—also called quantitative polymerase chain reaction (qPCR)—is one of the most powerful and sensitive gene analysis techniques available and is used for a broad range of applications including quantitative gene expression analysis, genotyping, SNP analysis, pathogen detection, drug target validation and for measuring RNA interference. Frequently, real-time polymerase chain reaction is combined with reverse transcription to quantify messenger RNA (mRNA) and MicroRNA (miRNA) in cells or tissues.

As the name suggests, real-time PCR measures PCR amplification as it occurs. This completely revolutionizes the way one approaches PCR-based quantitation of DNA and RNA. In traditional PCR, results are collected after the reaction is complete, making it impossible to determine the starting concentration of nucleic acid.

Real Time PCR vs Traditional PCR vs Digital PCR at a Glance​
Digital PCR​
Real-Time PCR​
Traditional PCR​
OverviewMeasures the fraction of negative replicates to determine absolute copy number.Measures PCR amplification as it occurs.Measures the amount of accumulated PCR product at the end of the PCR cycles.Quantitative?Yes, the fraction of negative PCR reactions is fit to a Poisson statistical algorithm .Yes, because data is collected during the exponential growth (log) phase of PCR when the quantity of the PCR product is directly proportional to the amount of template nucleic acid.No, though comparing the intensity of the amplified band on a gel to standards of a known concentration can give you 'semi-quantitative' results.Applications
  • Absolute Quantification of Viral Load
  • Absolute Quantification of Nucleic Acid Standards
  • Absolute Quantification of Next-Gen Sequencing Libraries
  • Rare Allele Detection
  • Low-Fold Copy Number Discrimination
  • Enrichment and Separation of Mixtures

  • Quantitation of Gene Expression
  • Microarray Verification
  • Quality Control and Assay Validation
  • Pathogen detection
  • SNP Genotyping
  • Copy Number Variation
  • MicroRNA Analysis
  • Viral Quantitation
  • siRNA/RNAi experiments
Amplification of DNA for:

  • Sequencing
  • Genotyping
  • Cloning
SummaryAdvantages of Digital PCR:

  • No need to rely on references or standards Desired precision can be achieved by increasing total number of PCR replicates
  • Highly tolerant to inhibitors
  • Capable of analyzing complex mixtures
  • Unlike traditional qPCR, digital PCR provides a linear response to the number of copies present to allow for small fold change differences to be detected
Adavantages of Real-Time PCR
  • Increased dynamic range of detection
  • No post-PCR processing
  • Detection is capable down to a 2-fold change
  • Collects data in the exponential growth phase of PCR
  • An increase in reporter fluorescent signal is directly proportional to the number of amplicons generated
  • The cleaved probe provides a permanent record amplification of an amplicon
Disadvantages of Traditional PCR
  • Poor Precision
  • Low sensitivity
  • Short dynamic range < 2 logs
  • Low resolution
  • Non-Automated
  • Size-based discrimination only
  • Results are not expressed as numbers
  • Ethidium bromide for staining is not very quantitative
  • Post-PCR processin



Senior Member
This seems to be a different lab. I've seen this lab previously and think it's been in relation to Lyme/co-infections testing. Co-operative Diagnostics was the lab that was offering XMRV testing last year and pulled it's test after their negative findings.