x-ray photoelectron spectroscopy was used to determine the elements ( o , c , n , p , and k ) in the outer 2 to 5 nm of the freeze-dried cell surface and showed that the hydrophilic character of the staphylococci was related to oxygen ( o/c ratio , approximately 0.52 ) - and phosphorus ( p/c ratio , approximately 0.03 ) -containing groups .
C0013879
elements
C0031705
phosphorus