Introduction
Pyrophosphate is widely present inside and outside the cell. The pyrophosphate in the cell mainly comes from mitochondria, which cannot pass through the cell membrane by free diffusion, and needs to be transferred to the outside of the cell through the progressive tonic protein channel on the cell membrane. Part of the extracellular pyrophosphate comes from the transmembrane transport of intracellular pyrophosphate, and the other part is generated by a series of extracellular enzymes located on the cell membrane.
Pyrophosphate, a natural substrate for alkaline phosphatase, is produced by many chemical reactions, such as hydrolysis of citrate and ATP, DNA replication and RNA polymerization, cyclic adenosine monophosphate (c-AMP) formation, and formation of fatty acid coenzyme A esters. Fluorescence-based pyrophosphate detection is simpler, more reliable, and more sensitive.
Material
• Pyrophosphate assay kit (Merck: MAK168)
• 96-well black opaque plate (Thermo Fisher: 237105)
• Feyond-A300 multi-mode microplate reader
Method
• Standard Preparation
Primary liquid concentration | Primary liquid volume μL | Diluent volume μL | Final standard concentration |
50mM | 10 | 490 | 1mM |
1mM | 50 | 450 | 100uM |
100uM | 45 | 105 | 30uM |
100uM | 15 | 135 | 10uM |
100uM | 4.5 | 145.5 | 3uM |
10uM | 15 | 135 | 1uM |
3uM | 15 | 135 | 0.3uM |
1uM | 15 | 135 | 0.1uM |
• Operation Steps
Prepare the Master Reaction Mix working solution according to the corresponding product instructions. Add 50ul of working solution to each well of a 96-well black flat-bottom microplate, and then add 50ul of pyrophosphate standard to each well, and set 3 duplicate wells for each standard. After mixing, incubate in the dark for 15 minutes, and start the instrument detection.
• Instrument Parameter Setting
Reagent wavelength | EX/EM: 316/456 |
PMT gain | Middle and high |
Stabilization time | 150ms |
Integration time | 40us |
Figure 1. Standard layout and parameter settings
Result
The built-in data processing software of Feyond-A300 can directly fit the standard curve between the concentration of pyrophosphate standard and the fluorescence intensity. Using the four-parameter (4PL) fitting method, the curve equation and curve fitting degree R² are given. The standard curve performs high-precision determination of samples without computer operation, and the report includes information such as standard curve and sample concentration.
Figure 2. Pyrophosphate standard curve
Summary
As a natural substrate, pyrophosphate plays an important role in a variety of physiological processes and is also closely related to a variety of diseases. Allsheng Feyond-A300 multi-mode microplate reader and high-precision kit can achieve accurate quantification of pyrophosphate.
Reference
[1] Liu Mengyuan, Wu Liling, Wang Jinyu Pyrophosphate and vascular calcification [J] Advances in Physiological Sciences, 2016, 47 (6): 5