MMP-2 from conditioned medium recovery in BSP-unbound fraction. Serum-free conditioned media collected from: 1) MDA-MB231, 2) rat bone marrow cells, 3) HT1080, and 4) human gingival fibroblasts were added to ELISA plates coated with indicated proteins (35 μM) and incubated at RT for one hour. Samples of bound (extract) and unbound (supernatant) proteins were extracted in SDS sample buffer and analyzed by zymography. Zymography shows that when MMP-2 is added to BSP-coated plates, both latent and active enzymes are recovered completely in supernatants. BSA and gelatin were used as negative and positive MMP-2-binding controls respectively.