Principle / Procedure

The NucleoSpin® RNA Blood Midi kit allows isolation of high-quality RNA from up to 1300 µL fresh or frozen whole blood. The working procedure is similar to the NucleoSpin® RNA Blood method and includes the simple and efficient direct total blood lysis and an effective rDNase digestion of contaminating DNA during the purification process. No selective erythrocyte lysis is needed and the whole procedure can be performed at RT.

NucleoSpin® RNA Blood Midi procedure

 

Features

Technology: Silica-membrane technology
Format: Midi spin columns
Sample material: 400–1300 µL whole blood (fresh or frozen)
Fragment size: > 200 nt
Typical yield: 3.9–26 µg (1300 µL whole blood)*
Typical yield (A260/A280): 1.9–2.1
Elution volume: 200–400 µL
Preparation time: 75 min/6 preps
Binding capacity: 700 µg

* RNA yield strongly depends on the leukocyte number in each individual blood sample.

    

Application data

High yield and quality – very convenient handling – high flexibility in sample volume and sample type
NucleoSpin® RNA Blood kits are based on a simple and convenient direct blood lysis. This procedure allows a very effective blood cell lysis at room temperature without an upstream selective erythrocyte lysis at 4 °C. Compared with competitor kits, NucleoSpin® RNA Blood kits show higher yields from smaller sample volume. In addition it is possible to obtain a linear increase of yield in regard to sample volume. Both fresh and frozen blood samples can be used to purify RNA with comparable yield and quality.

	Higher yield from smaller sample volume – comparison to competitor kits RNA was isolated from the indicated blood volumes following each manufacturer's protocol. The quality of isolated RNA is comparable. Average RIN numbers (data not shown) were: 7.5 (Q); 7.7 (NucleoSpin® RNA Blood); 8.8 (NucleoSpin® RNA Blood Midi); 8.9 (Q, PAXgene®).
	Proportional increase of yield in regard to sample volume NucleoSpin® RNA Blood Midi has been used to isolate RNA from 400, 700, and 1300 μL blood (EDTA) aliquots from three different donors (Blood A–C). Yield increases proportionally to the sample volume used, indicating the high efficiency and reliability of this procedure.
	Isolation of highly pure RNA Highly pure RNA has been isolated from 1300 µL whole blood (EDTA) using NucleoSpin® RNA Blood Midi. Blood samples derived from three different donors and isolations were done in duplicates. The purity of the isolated RNA was determined by spectrophotometric measurement of absorption at 260 nm, 280 nm, and 228 nm. On average the A260/A280 ratio was 1.99 (±0.04) and the A260/A228 ratio was 2.03 (±0.08).