Clear Separation of Cytosolic and Nuclear Fractions from Adipose/Carcass Tissue of Drosophila Using NT-032

(Invent Biotechnologies Inc.)

Kong et al. (NF-κB restrains nutrient-dependent transcription programs through chromatin modulation in Drosophila. bioRxiv, 2025-10.) explored how the Drosophila NF-κB homolog, Relish, modulates nutrient-dependent transcriptional programs through chromatin remodeling. The study demonstrates that NF-κB functions as a transcriptional repressor that limits the overactivation of nutrient-responsive genes in nutrient-rich conditions. This work reveals a key mechanistic link between metabolic signaling and chromatin-based gene regulation.

Using transcriptomic and chromatin accessibility analyses (ATAC-seq and RNA-seq), the authors showed that NF-κB (Relish) reduces chromatin accessibility at promoters and enhancers of nutrient-regulated genes. In the absence of Relish, these genomic regions become more open, leading to increased transcriptional activity of metabolic genes.

This modulation ensures transcriptional balance in response to nutrient availability, preventing metabolic overactivation. The findings redefine NF-κB’s role beyond immunity—establishing it as a chromatin-associated regulator of metabolic homeostasis. A critical component of this research was the clean separation of nuclear and cytosolic fractions from Drosophila tissues to study chromatin-associated NF-κB activity. The authors utilized the Invent Biotechnologies Cytosolic and Nuclear Extraction Kit (NT-032), a kit designed for rapid and clean isolation of intact nuclei.

The NT-032 kit played an essential role in ensuring the purity and integrity of the nuclear fraction, which is a prerequisite for high-quality assays. The clean separation of nuclear and cytosolic compartments minimized cross-contamination, allowing precise assessment of NF-κB’s chromatin-bound fraction and its regulatory impact on gene expression.

For Drosophila tissues—particularly the adipose/carcass tissue, which are small, metabolically active, and difficult to homogenize—the NT-032 kit’s gentle mechanical and buffer-based fractionation ensured efficient recovery of nuclear proteins. This high-quality preparation enabled the authors to confidently link NF-κB activity to nuclear chromatin modulation rather than cytosolic signaling artifacts. This study provides a new understanding of how NF-κB signaling integrates nutrient sensing with chromatin-level transcriptional control. The use of the NT-032 kit contributed to the reproducibility and clarity of the nuclear analyses.;

For researchers examining chromatin-mediated regulation in small or heterogeneous tissues, Kong et al. (2025) illustrate the importance of clean fractionation methods. The NT-032 kit exemplifies an efficient kit that enhances nuclear purity, improves yield, and supports consistent data quality across cytosolic and nuclear experiments.