The motivation behind the work is rooted in a growing tension in modern biomedical research. High-throughput technologies such as whole-genome sequencing, RNA sequencing, and metabolomics have dramatically increased the demand for high-quality tissue samples, yet storage space in biobanks remains finite. When a single original sample must be divided into aliquots for multiple downstream assays, researchers face a difficult trade-off: set aside too little material and future experiments may fail, or set aside too much and waste limited freezer capacity. Until now, systematic data on the biomolecule yields from fresh tissues have been surprisingly scarce. Previous studies had reported yields from autopsy-derived or formalin-fixed specimens, but long-term storage and chemical fixation can degrade nucleic acids and proteins, making those estimates unreliable for fresh or cryopreserved material.

To fill this gap, the team euthanized six wild-type C57BL/6J mice and six BALB/c nude mice and collected fresh tissue from fourteen organ types, including bone, colorectum, heart, kidney, liver, lung, lymph node, muscle, ovary, skin, spleen, stomach, thymus, and uterus. Because BALB/c nude mice lack a functional thymus and have minimally developed lymph nodes, only twelve tissue types were collected from that strain. Tissue weights ranged from 6 to 45 milligrams, and larger samples were homogenized using a mixer mill until no visible lumps remained. DNA and RNA were extracted separately using commercial column-based kits, while total protein was isolated using radioimmunoprecipitation assay buffer, with a specialized protocol for bone that involved grinding the tissue under liquid nitrogen and applying ultrasound in an ice bath.

Quality control was rigorous. Nucleic acid concentration and purity were assessed with a NanoDrop One spectrophotometer, DNA integrity was evaluated by agarose gel electrophoresis, and RNA quality was measured by capillary electrophoresis using a Fragment Analyzer. Protein concentrations were determined with the bicinchoninic acid assay, calibrated against a standard curve with an R-squared value of 0.996. The results showed that nearly all DNA and RNA samples fell within the accepted purity range of 1.8 to 2.1 for the 260/280 nanometer ratio, with no statistically significant differences among tissue groups in either strain, confirming that a single standardized protocol can consistently yield high-purity nucleic acids regardless of organ origin.

The yield data, however, told a strikingly different story. In C57BL/6J mice, DNA yields were highest in the colorectum at 2.45 micrograms per milligram of tissue, followed closely by the spleen and kidney, while bone produced the lowest yield at just 0.22 micrograms per milligram. In BALB/c nude mice, the pattern shifted: the stomach delivered the highest DNA yield at 4.60 micrograms per milligram, with the colorectum and uterus close behind, and bone again at the bottom with 0.51 micrograms per milligram. RNA yields followed a similar tissue-dependent pattern, peaking in the colorectum of C57BL/6J mice at 3.46 micrograms per milligram and in the spleen of BALB/c nude mice at 3.79 micrograms per milligram, with bone consistently producing the least. Protein yields were highest in the kidney and liver of C57BL/6J mice and in the liver of BALB/c nude mice, reaching up to 192.31 micrograms per milligram, while bone again lagged far behind.

To make these findings immediately actionable, the researchers calculated the exact tissue masses required to obtain 10 micrograms of DNA, 10 micrograms of RNA, and 1 milligram of protein from each organ type in both strains. These thresholds correspond to common experimental requirements: a comprehensive PCR experiment including multiple targets, replicates, and standard curves can consume 10 to 100 micrograms of DNA, while real-time PCR and RNA sequencing typically require around 10 micrograms of RNA. Because weighing tiny tissue fragments manually is often impractical, the team also provided visual references comparing the needed tissue sizes to everyday objects such as sesame seeds, grains of rice, and mung beans. For example, in C57BL/6J mice, 5.71 milligrams of thymus tissue—roughly the size of a single sesame seed—is sufficient to yield 10 micrograms of DNA, while 6.73 milligrams of lung tissue is enough for 10 micrograms of RNA.

The correlation analysis confirmed a positive relationship between starting tissue weight and biomolecule yield within each tissue type, validating the predictive power of the baseline values. When the researchers compared yield patterns between the two mouse strains, they found a weak positive correlation for DNA yields but strong positive correlations for RNA and protein yields, suggesting that despite genetic and immunological differences between the strains, the underlying cellular composition of most organs drives similar extraction efficiencies for these two biomolecule classes.

The implications for biobank management are significant. For organs that yield high amounts of DNA, RNA, and protein—such as the colorectum, spleen, liver, and kidney—both storage volume and physical sample size can be reduced without compromising downstream applications. Conversely, for low-yield tissues like bone and muscle, larger storage volumes and sample sizes are recommended. This evidence-based approach to sample allocation is particularly valuable for small or rare organ types, where every milligram counts. The authors also noted that tissues with high nuclease activity, including the colorectum, spleen, stomach, and thymus, showed mild DNA or RNA degradation in their quality assessments, and they recommend incorporating nuclease inhibitors or rapid freezing in liquid nitrogen to preserve biomolecule integrity in freshly collected samples.

The study is not without limitations. The sample size of six mice per group may not fully capture biological variability, and certain tissue types such as bone and skin exhibited relatively high coefficients of variation, likely reflecting their inherent structural heterogeneity and the technical challenges of complete homogenization. The extraction protocols used—while widely adopted and compatible with applications including PCR, whole-genome sequencing, and whole-genome bisulfite sequencing—represent only one set of methods, and alternative approaches such as the TRIzol method for RNA extraction may yield different results. The authors also caution that factors including the physiological state of the tissue, the presence of disease or necrosis, and the choice between cryopreservation and paraffin embedding can all influence yields, meaning the conclusions are most directly applicable to experimental systems similar to those used here.

Nevertheless, the baseline values established in this study provide a practical foundation for the rational preservation and management of mouse tissue samples. By defining tissue-specific minimum masses required for reliable extraction of each biomolecule class, the data help minimize waste while ensuring adequate material for future research. As biobanks worldwide grapple with ever-growing collections and limited storage capacity, this systematic yield map offers a welcome tool for making every milligram of preserved tissue count.

Subject of Research: Baseline DNA, RNA, and protein extraction yields from fourteen mouse tissue types in two laboratory strains

Article Title: The yields of nucleic acids and proteins extracted from various murine tissue types

Article References: The yields of nucleic acids and proteins extracted from various murine tissue types. (n.d.). https://doi.org/10.3389/abp.2026.16122

Image Credits: AI Generated

DOI: 10.3389/abp.2026.16122

Keywords: DNA yield, RNA yield, protein extraction, mouse tissue, biobank, C57BL/6J, BALB/c nude mice, tissue preservation, molecular biology, sample allocation, biomolecule quantification, laboratory methods