Human Basic Salivary Proline Rich Protein 4/PRB4 ELISA Kit

From Assay Genie, this human-reactive Sandwich ELISA kit uses a double-antibody format with colorimetric detection to quantify Basic Salivary Proline-Rich Protein 4 (PRB4), also known as Po, BstNI type basic salivary proline-rich protein 4, Parotid o protein, Salivary proline-rich protein II-1, and Proline-rich peptide IB-5. The kit accepts serum, plasma, cell culture supernatant, cell or tissue lysate, and other liquid samples, with a quoted sensitivity of 46.875 pg/mL and a working range of 78.125-5000 pg/mL; reagents are stored at 2-8°C for 12 months.

Proline-rich proteins such as PRB4 contribute to oral health through saliva lubrication, remineralisation of tooth enamel, and defence against pathogens, so monitoring PRB4 offers insights into the oral microbiome and supports the diagnosis and treatment of oral diseases. Linearity across serial dilutions was demonstrated for serum (85-105% at 1:8), EDTA plasma (82-99% at 1:2 to 84-101% at 1:8) and heparin plasma (80-98% at 1:2 to 87-100% at 1:8), while recovery averaged 94% in serum, 99% in EDTA plasma, and 95% in heparin plasma.

The workflow uses a pre-coated plate with primary incubation at 37°C for 90 minutes, a biotin-labelled detection antibody step at 37°C for 60 minutes, HRP-Streptavidin binding for 30 minutes, TMB substrate development in the dark for 10-20 minutes, and absorbance measurement at 450 nm after addition of stop solution. Sample preparation guidance covers clotting and centrifugation at 1000 × g for 20 minutes for serum, anticoagulant collection with centrifugation at 1000 × g for 15 minutes at 2-8°C for plasma, plus workflows for tissue homogenate, cell culture supernatant, and cell lysate.