Optimizing Sample Homogenization | The Scientist Magazine®

Researchers in numerous fields need to extract molecules of interest from samples for further analysis. A critical, early step in the isolation procedure is tissue homogenization or cell disruption, the process in which cells are lysed to release intracellular analytes, such as nucleic acids, proteins, or metabolites. These molecules can be analyzed using various techniques, including PCR, NGS, and western blot. As these analysis methods all hinge on efficient and reproducible sample preparation, optimization of this step is a priority.

Challenges with Existing Homogenization Methods

The most traditional homogenization technique involves the mechanical pulverization of tissue samples using a mortar and pestle. However, this procedure is time consuming, laborious, and may not be optimal depending on the physico-chemical properties of the sample.¹ Non-mechanical methods, including chemical lysis and sonication, can also homogenize samples. However, the heat generated through sonication and the detergents used in chemical lysis can be harsh on fragile molecules, such as RNA.^1,2

More recently developed mechanical methods reduce the labor and time required for lysis, as well as increase the homogenization efficiency. For instance, 3D bead-beating technology uses rapidly-accelerated bead movement to grind tissue samples.¹ The beads inside the lysing tubes are agitated through an oscillating multi-directional movement. Additionally, a large assortment of lysing kits are available and offer opportunities to homogenize any kind of biological sample. These kits include tubes ranging in volume from 0.3 to 15 mL, as well as beads composed of ceramic, glass, or stainless steel, which vary in diameter.

Problematic Sample Properties

In addition to the challenges associated with the chosen lysis method, a sample’s properties can also hinder analyte extraction. Some samples only yield a small quantity of analytes, such as DNA from sperm cells. Consequently, researchers need to process larger sample volumes, which take more time to homogenize and may exceed the instrument’s maximum volume limits. Additionally, some samples, such as seeds, skin, bone, or tumor-derived tissue, are difficult to homogenize due to their hardness, elasticity, mineralization, or fibrous nature.^1,3–5 Further exacerbating the problem, samples that are difficult to lyse generate more heat, leading to the degradation or denaturation of some thermosensitive analytes.

The Solution to Homogenizing Difficult Samples

The Precellys® Evolution Touch is a versatile homogenizer from Bertin Technologies. It uses bead-beating technology, which is the gold standard for tissue homogenization, to grind even the most difficult samples, such as teeth and hair, within a few minutes. It is capable of processing samples of varying sizes, weights, and volumes. Moreover, it can homogenize up to twenty-four samples simultaneously. As the instrument’s symmetry allows all the tubes to follow the same motion, it ensures equal homogenization efficiency for each sample. The Precellys® Evolution Touch is equipped with a touchscreen that is responsive even when the user is wearing gloves. Additionally, researchers can choose between thirty different lysing kits designed to homogenize samples of various properties and volumes. Thanks to speeds up to 10,000 rpm, minimal heat is generated through the samples, thereby ensuring the safety of thermosensitive analytes. Furthermore, the instrument is compatible with the Cryolys Evolution cooling unit, which allows it to maintain the sample temperature between 0 and 10 °C before and during homogenization.

Based on the variety of tube sizes accepted, the numerous lysing kit options, and the ability to process multiple samples simultaneously, the Precellys® Evolution Touch is a versatile and efficient homogenizer suitable for many research fields.

References

1. Pagani S, Maglio M, Sicuro L, Fini M, Giavaresi G, Brogini S. RNA Extraction from Cartilage: Issues, Methods, Tips. Int J Mol Sci. 2023;24(3):2120. doi:10.3390/ijms24032120
2.  Shehadul Islam M, Aryasomayajula A, Selvaganapathy PR. A Review on Macroscale and Microscale Cell Lysis Methods. Micromachines. 2017;8(3):83. doi:10.3390/mi8030083
3.  Zelentsova EA, Yanshole VV, Tsentalovich YP. A novel method of sample homogenization with the use of a microtome-cryostat apparatus. RSC Adv. 2019;9(65):37809-37817. doi:10.1039/C9RA06808B
4. Reno C, Marchuk L, Sciore P, Frank C b., Hart D a. Rapid Isolation of Total RNA from Small Samples of Hypocellular, Dense Connective Tissues. BioTechniques. 1997;22(6):1082-1086. doi:10.2144/97226bm16
5. Duressa D, Rauscher G, Koike ST, et al. A Real-Time PCR Assay for Detection and Quantification of Verticillium dahliae in Spinach Seed. Phytopathology. 2012;102(4):443-451. doi:10.1094/PHYTO-10-11-0280