False-positive staining

Be sure to remove the extraembryonic membrane. Failure to do this may result in the lower colorimetric detection due to the reduced penetration of the probe. If technically difficult, the extraembryonic membrane should be at least partially torn. Additionally, be sure to puncture the vesicular structures such as brain, heart, and otic vesicles to prevent the false-positive staining caused by trapping of the probe. 

Other benefits of polymer-based methods are also worth noting. Since this is a biotin-free system, the problems of false-positive staining due to endogenous biotin are overcome.Therefore, the efficiency of AR may be increased without the risk of evoking endogenous biotin activity. Furthermore, compared with three-step procedures, the technique is simpler, and assay time is decreased. Because of this, the risk of errors is reduced and reproducibility is increased. 

Sensitivity of immunological stain = 96% = 0.96 False-negative error rate of the test = 4% = 0.04 Specificity of the test = 94% = 0.94 False-positive error rate of the test = 6% = 0.06 Prevalence of effect in the tissues = 1% = 0.01... 

Weak false-positive nuclear staining may occur with some monoclonal or polyclonal antibodies therefore, careful assessment of the reaction pattern with particular attention to the staining of the normal cells is recommended. False-positive nuclear staining may be accentuated if the slides are allowed to dry during the staining procedure. 

Finally, a few published reports indicate that antigen retrieval at extremely high temperatures may result in nonspecific staining. Baas et al. (1996), for example, have reported false-positive results at a very high antigen retrieval temperature using monoclonal... 

A large number of cell types and their corresponding tumors may display positive staining for proteins that are not anticipated. In this context the staining is called false positive, aberrant or cross-reactive and can potentially lead to incorrect diagnosis. 

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