The Alkphase-B immunoassay (Metra Biosystems, Inc.) is a single monoclonal antibody-based assay that measures bone ALP in serum.
At designated time intervals, an aliquot was brought to room temperature and assayed for bone ALP in the Tandem-MP Ostase, Tandem-R Ostase, and Alkphase-B immunoassays.
For each method, samples were assayed using Tandem-MP Ostase, Tandem-R Ostase, Alkphase-B, and total ALP assays.
Similar bone ALP instability at -20 [degrees]C was observed with the Alkphase-B assay (Fig.
For these same serum samples, the slope ratios were 16.7% for the Tandem-R Ostase assay and 14.9% for the Alkphase-B assay.
A similar ratio was observed for the Tandem-R Ostase assay (36 [micro]g/L per 100 U/L of total ALP activity), whereas a ratio of 47 U/L bone ALP per 100 U/L of total ALP activity was obtained for the Alkphase-B assay.
Identical results were obtained for the Tandem-R Ostase assay, whereas 4.7 [+ or -] 0.5 U/L per 100 U/L of total ALP activity was observed for the Alkphase-B assay.
However, bone ALP, when detected using the activity-based Tandem-MP Ostase and Alkphase-B assays, does not show the same stability profiles as seen with the Tandem-R Ostase assay.
Serum liver ALP reactivity was found to be similar in the Tandem-MP Ostase, Tandem-R Ostase, and Alkphase-B immunoassays.
In addition, Metra gains the rights under the Beckman Coulter patents to continue to make, use and sell the Alkphase-B
formation market currently marketed by Metra on a worldwide basis.
In patients with chronic hepatic failure (and no evidence of metabolic bone disease) a BAP enzyme immunoassay ("Alkphase-B
") was the only alkaline phosphatase assay showing a lack of significant increase in BAP in women over the values seen in the male reference subjects (indicating no clinically relevant cross-reactivity of the assay) .