Isolation of high-quality RNA from Platycladus orientalis and other Cupressaceae plants

Platycladus orientalis has a lifespan of several thousand years in China, making it a good plant in which to study aging at the molecular level, but this requires sufficient quantities of high-quality P. orientalis RNA. However, no appropriate methods have been reported for total RNA isolation from P. orientalis leaves. The TRIzol method did not extract RNA, while cetyltrimethylammonium bromide, sodium dodecyl sulfate-phenol, and plant RNAout kit (Tianz, Inc., China) protocols resulted in low yields of poor quality RNA. Isolating total RNA using the Spectrum™ Plant Total RNA Kit (Sigma-Aldrich, St. Louis, MO, USA) resulted in a high-quality product but a low yield. However, the two-step removal of polyphenols and polysaccharides in the improved plant RNAout kit protocol resulted in the isolation of RNA with a 28S:18S rRNA ratio of band intensities that was ~2:1, the A260/A280 absorbance ratio was 2.03, and the total RNA yield from P. orientalis leaves was high. This protocol was tested on different P. orientalis tissues of different ages and on leaves of five other Cupressaceae plants. The total RNAs were successfully used in complementary DNA synthesis for transcriptome sequencing and would be suitable to use in additional experiments. The results of this study will benefit future studies in Cupressaceae plants.

Isolation of high quality RNA from Polyporus umbellatus (Pers. ) Fries

Background: The dried sclerotium of medicinal fungus Polyporus umbellatus (Pers.) Fries has many pharmacological functions such as diuretic and anticancer activity, in which high-content polysaccharides may play an important role. However, RNA isolation is difficult in filamentous fungi and lacking in P. umbellatus. Results: Five methods for RNA extraction from five strains collected from four provinces were assessed for their ability to recover a high-quality RNA applicable for sequence-related amplification polymorphism (SRAP) PCR and GDP-D-mannose pyrophosphorylase (GMP) gene expression profiles. Both A260/A280 and A260/A230 ratios of the best Trizol Plus + RNAiso-mate for Plant Tissue method are around 2 with a yield of 1122.00 +/- 0.21 ng ul-1. The Trizol method also showed good quality with the yield 469.60 ng ul-1. The SRAP PCR amplified clear and polymorphic bands in all five cDNA samples transcribed from RNA by using primer Me4-Em4. GMP gene fragment (1251 bp) was successfully amplified by RT-PCR, suggesting the integrity of isolated RNA. Conclusion: All these results showed that the total RNA isolated by this protocol is of sufficient quality for subsequent molecular applications.

Improved isolation of good-quality total RNA from the optic stalk of mud crab, scylla paramamosain

An improved and efficient protocol was developed based on the TaKaRa RNAiso Plus Kit (Code: D9108A) for isolating good-quality total RNA from the optic stalk of mud crab, Scylla paramamosain. The protocol was based on the Trizol method with modifications. The carapace overlapping the optic stalk was retained with RNA in regular protocol. In order to remove the abundant deposition correlative with the carapace which makes the isolation of RNA particularly difficult, 5M potassium acetate solution (pH = 6.0) was added before the precipitation of RNA, and the temperature of RNA deposition was also decreased to -70ºC to ensure the stabilization of RNA. Good-quality total RNA from the optic stalk of S. paramamosain could be easily isolated with this modified protocol and three conventional methods were also employed to confirm the quality of RNA. This improved method would be helpful in facilitating molecular research of crabs involving RNA from the optic stalk.