Hi, qPCR is better. You need a minimal level of DNA or RNA.

PCR I think

Hi Hagir. PCR is better because of higher sensitivity but due to its extreme sensitivity, it is prone to contamination leading to false positives in the specimens. Immunohistochenistry is thought to be gold standard in establishing diagnosis. Though one can improve PCR by use of TaqMan probes or other strategies, the end result will depend on our requirements from the query. IHC is highly specific and PCR is highly sensitive. One can also do a two stage diagnosis using PCR as a screening test and IHC as confirmatory one.

Good luck

Amended on 15 April 2018

I would like to recommend to use the PDMD method based upon famous Edman-degradation method (please see file; HepG2 fucoidan). I must repeatedly declare that Immunohistochemistry and PCR are not quantitative at all. Binding protein IgG and avidin are unexpectedly non specific. Avidin binds biotin, lipoic acid and many amini acids. Enzyme (lipoamidase) has been found that it recognizes multiple substrates (please see file; Multiple Hydrolase LIP). Therefore, the method using an enzyme of thermostable DNA polymerase chain reaction (PCR) can not become quantitative producing many DNAs containing many false DNA-sequences. Further, Dr. Makoto Iwaya (Harvard University, Cambridge, MA, USA and National Children's Medical Research Center, Setagaya-ku, Tokyo, Japan) has informed personally that the PCR method is not applicable to amplify the trace DNA from white blood cell or Leukocyte of neonates.

By the way, I have studied 4 liver tissues. Liver of named No.6 (who has survived; may be due to absence of HIV-1, though SIV is present) has surely contained HCV as assessed both by PCR method (clinical laboratory of the Hospital) and by our PDMD method. Other three liver tissues has contained HCV as assessed by quantitative PDMD method, but PCR method can not show the presence of HCV; i.e., liver of pseudo liver cancer has Genome polyprotein (HCV) at 4.4 μg/mg of tissue protein, liver (with leprosy) has Genome polyprotein (HCV) at 21.9 μg/mg of tissue protein, liver (with PBC) has Genome polyprotein (HCV) at 35.4 μg/mg of tissue, but non-quantitative PCR method can not indicate the presence of HCV at all. Thus, notorious PCR method has given 3 false-negative results among 4 specimens.

Further, HepG2 has Genome polyprotein (HCV) at 7.8 μg/mg of cell protein and does not have HBV as determined by PDMD method, although many reports based upon ELISA or PCR have false-positively published that HBV is present in HepG2. Therefore, notorious PCR and ELISA methods are considered to be non reliable.

I would like to express my opinion. dsDNA virus (such as HHVs including HHV-5 and HBV) seems not to be the cause of cancer. Thus, human papillomavirus (HPV) may not to be the cause of cervical cancer; i.e., non-quantitative immunological and qPCR methods, and the use of parametric statistics, which uses normal or Gaussian distribution, seems to have induced the false conclusion. Therefore, vaccine against HPV may not effect to prevent cervical cancer at all.

Similarly, SV-40 (dsDNA virus; Simian Vacuolating Virus 40 or Simian Virus 40) and SeV (-ssRNA virus; Murine Parainfluenza Virus type 1 or Hemagglutinating Virus of Japan (HVJ)) can not induce the cancer.

Stomach cancer seems not to be induced by bacterium of Helicobacter pylori, but seems to be induced by co-infection of HIV-1 and +ssRNA phage of Helicobacter pylori or +ssRNA virus of Flavivirus Classical Swine Fever Virus (CSFV; Hog Cholera Virus).

Quantitative PDMD method has clearly indicated that human hepatocellular carcinoma (HCC) has been occurred by the co-infection of HIV-1 (human-specific retrovirus) and human-specific flavivirus of HCV (+ssRNA uirus) (both viruses have envelope compartment: please see again the file; HepG2 fucoidan). Moreover, precise genes or proteins have been identified and described; i.e., Gag-Pol polyprotein of HIV-1 (RT and integrase genes are present) and Genome polyprotein (peptidase gene is present) of HCV (please see file; The Fascio effect).

Thank you all for your responses