QIAGEN Genomic-tip System

The QIAGEN Genomic-tip system is designed for small- to large-scale purification of high-molecular weight genomic and mitochondrial DNA from a wide range of biological samples including blood, tissue, cultured cells, yeast, and bacteria, using gravity-flow Genomic-tips.

Features and benefits

10–500 µg of pure genomic DNA
Reliable isolation of DNA up to 150 kb
No phenol or chloroform extractions
Convenient, parallel processing of multiple samples

QIAGEN Genomic-tip Specifications
Sample source	QIAGEN Genomic-tip	Yield (µg)	Sample source	QIAGEN Genomic-tip	Yield (µg)
Whole blood (human)			Yeast (S. cerevisiae)
1 ml	20/G	15-20	1 ml	20/G	18-20
5 ml	100/G	80-100	5 ml	100/G	85-95
20 ml	500/G	350-400	20 ml	500/G	350-450
Cultured cells (HeLa)			Gram– bacteria (E. coli)
5 x 106	20/G	15–20	0.6–1.2 ml	20/G	16–20
2 x 107	100/G	80–100	3–6 ml	100/G	8–95
1 x 108	500/G	350–450	15–30 ml	500/G	300–400
Tissue (liver)			Gram+ bacteria (B. subtilis)
15 mg	20/G	15-20	1.2-1.8 ml	20/G	16-20
80 mg	100/G	80-100	6-9 ml	100/G	85-95
350 mg	500/G	350-450	30-45 ml	500/G	300-400

Principle

QIAGEN Genomic-tips use unique QIAGEN anion-exchange technology to purify high-molecular-weight DNA from a wide range of biological samples without phenol or chloroform. Lysis buffers are optimized for different sample types and provide immediate denaturation of proteins such as nucleases, histones, and DNA-binding proteins, as well as potentially infectious viral particles. Under the pH and low-salt conditions provided by the buffer, DNA binds to the QIAGEN Resin in the column while other cell constituents such as proteins, carbohydrates, and metabolites flow through. Purified DNA is eluted in high-salt buffer. Genomic-tips operate by gravity flow, and can be left unattended without running dry. This reduces hands-on time to a minimum and makes the procedure ideal for simultaneous processing of multiple samples.

Procedure

Samples are first lysed (tissue samples are mechanically disrupted) and proteins simultaneously denatured in the appropriate lysis buffer (see flowchart "QIAGEN Genomic-tip procedure"). QIAGEN Protease or Proteinase K is then added and after a suitable incubation period, lysates are loaded onto the QIAGEN Genomic-tip. DNA binds to the column while other cell constituents pass through. Following a wash step to remove any remaining contaminants, pure, high-molecular-weight DNA is eluted and precipitated with isopropanol. Hands-on time for the complete procedure is just 20 minutes for bacteria, 30 minutes for blood and cultured cells, and 40 minutes for tissue and yeast.

Downstream applications

The QIAGEN Genomic-tip procedure is very gentle and results in negligible DNA shearing. DNA purified with QIAGEN Genomic-tips is sized up to 150 kb with an average length of 50–100 kb (see figure "Genomic DNA of up to 150 kb"). The DNA is free of all contaminants such as RNA, protein, and metabolites, and has A260/A280 ratios between 1.7 and 1.9, making it well suited for use in the following applications:

RFLP analysis
Analysis of gene targeting
Screening of transgenic animals
DNA fingerprinting studies
Southern blotting
PCR amplification
Direct bacterial-genome sequencing (see figure "Direct Sequencing of Bacterial Genomic DNA")

Genomic DNA of up to 150 kb

Pulse-field gel electrophoresis of DNA (2 µg) purified using QIAGEN Genomictips. M: markers.

Direct Sequencing of Bacterial Genomic DNA

Direct sequencing of E. coli genomic DNA purified on a QIAGEN Genomic-tip 100/G. 2.5 µg genomic DNA was sequenced with a 22mer primer which hybridizes to sequences within the atpB gene. Sequencing reactions were performed using a modified BigDye Terminator cycle sequencing protocol.