passages.id: split_4_test_2419_passage
passages.type: progene_text
passages.text: In the current study , analytic gel permeation FPLC , azido photoaffinity labeling , two - dimensional ( 2-D ) gel electrophoresis , and matrix - assisted laser desorption / ionization mass spectrometry ( MALDI - MS ) have been used to examine the biochemical relationship between the 80 - kDa RNase L in healthy control PBMC and the 37 - kDa RNase L in PBMC from individuals with CFS .