Other potential sources of bias which could have influenced our finding include the genetic heterogeneity of HIV-1, which can impede the accuracy of quantitation, especially in early assays primarily designed to detect subtype B [20] [22].
Early assays lacked standardization, substantially limiting the use of HbA1c in patient care.
In the early assays, significant differences were actually in the opposite direction than predicted by ecological speciation.
Various antibody based assays have been developed but these were tailored for animal cells and the early assays detected spurious components in non-animal cells [ 9].
Due to the nature of the infection and the sensitivity of these early assays, infection could not be confirmed for up to 3 months after exposure.
Early assays used a pH of 7.4 [ 2] which was later decreased to 5.5 - 6.0 to improve sensitivity [ 3, 4] and angiotensinase inhibition [ 5].
The results of such assays mean that the circulating levels of VEGF-A found in normal plasma are regularly reported at variously between 0 and 200 pg/ml, whereas early assays using enzyme immunoassays (EIA) or differential epitope antibodies put the concentration at >1 ng/ml.
Early assays of ER were performed using ligand (oestradiol -binding assays (LBAs), which are technically difficult, require relatively large amoestradiol -bindingzen tissue, assaysn be compLBAsted by prolonged delays to freezing and variable amounts of cancer whichn the tissue.
