False positive susceptibility

May be recovering from acute HBV infection (2) May be distantly immune and test is not sensitive enough to detect very low level of anti-HBs in serum (3) May be susceptible with a false-positive anti-HBc (4) May be undetectable level of HBsAg present in the serum and the person is actually a carrier. 

Immunochemical approaches are cheaper, readily adaptable, rapid, portable, and reduce the need for expensive analytical equipment. They can also be used to simultaneously assay a large number of samples over a short period of time. One of the major factors that still hmits the use of this technique in the detection of a wider range of PPCPs in the environment is the lack of suitable antibodies sensitive to most PPCPs that occur in the environment. Furthermore, immunoassay accuracy can be susceptible to cross reactions and other effects from the matrix, giving false positives in some instances (Huang and Sedlak, 2001). Thus, it is recommended that immunoassay analytical results be validated with GC- or LC-based methods. 

In individual compound analysis with the FID, analyte identification relies solely on retention time. As a result, single compound determinations (for example, individual phenols or PAHs) are usually gravely affected by interferences that often render the results unreliable or unusable. Because the FID methods for individual compound analysis are so susceptible to false positive results, they should be used with caution and only for interference-free matrices. 

Anti-HBs (-) 2. Distant immunity and test not sensite enough to detect low level ot insemm 3. Susceptible with false-positive anti-HB 4. May have undetectable level of HB g in semm and be chronically infected... 

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