Godin:Protocols/NIST traceable particle size standard

From OpenWetWare
Jump to navigationJump to search

Home        Calendar        Contact        Lab Members        Protocols        Publications        Research        Orders       


  • Safety goggles
  • Latex or nitrile gloves



These microspheres are used to calibrate instrumentation. At 0.01x concentration of 1.51µm beads, we have just over 5 billion particles per ml:

[math]\displaystyle{ {\frac{10~\mathrm{mg}}{1~\mathrm{mL~solution}}}\cdot\frac{1~\mathrm{g}}{1000~\mathrm{mg}}\cdot \frac{1~\mathrm{cm}^3}{1.05~\mathrm{g}}\cdot \frac{1~\mathrm{particle}}{\frac{4}{3}\pi(\frac{1.51\times10^{-4}~\mathrm{cm}}{2} )^3}=5.3\times10 ^9~\mathrm{particles/mL} }[/math]


This is pretty straight-forward. Simply dilute the beads to the desired concentration. The NIST particles should be kept in the refrigerator to prevent the growth of contaminants. Also, be sure to use the vortex mixer to fully dissolve all the microspheres; they tend to clump together when left alone for awhile.