PF-04523655

The high-salt/hypotonic fractionation method for nuclear protein extraction is based on the differential solubility of cellular components. Cytoplasmic proteins are extracted first using a hypotonic buffer that causes cell swelling and membrane rupture, followed by centrifugation to separate the cytoplasmic supernatant from the nuclear pellet. The nuclear pellet is then subjected to high-salt extraction (e. g. , 0. 4 M (NH4)2SO4 or 1 M NaCl) to solubilize tightly bound nuclear matrix proteins, including transcription factors, histones, and structural proteins associated with chromatin and the nuclear scaffold. This approach allows for the isolation of both soluble cytoplasmic proteins and salt-resistant nuclear proteins while minimizing cross-contamination.

RNA interference (RNAi) is a cellular mechanism that inhibits gene expression by suppressing gene transcription or activating RNA degradation. This mechanism was discovered in plants in 1998 by Andrew Fire and Craig Mello. Today, this phenomenon can be observed in almost all eukaryotes, including protozoa, flies, nematodes, insects, parasites, and mammals.