Monomeric size of soluble LIGHT. To determine the monomoric size of soluble LIGHT, supernatants of PMA (100 ng/ml + ionomycin 1 μg/ml) activated PBMCs were collected after 48 hours and concentrated with Microcon centrifugal filters YM50. Soluble LIGHT production in supernatant was then assessed by ELISA. Molecular mass of monomeric LIGHT was detected by Western blotting. 50 ng of recombinant sLIGHT were loaded in one lane as a control (Figure 4).