Comparative Review of Dharmacon, Genscript, Whitehead Websites for RNAi Design

Title: Dharmacon, Genscript, Whitehead

URL: http://www.dharmacon.com/

     http://www.genscript.com/index.html

     http://jura.wi.mit.edu/siRNAext/

Date Reviewed: May 24,2004

Description:

Dharmacon touts itself as the worldŪs largest provider of synthetic siRNA and custom RNA oligos. Dharmacon offers an extensive product line including pre-synthesized reagents and designed siRNAs targeting all unique human genes in the NCBI RefSeq database. Also available are starter kits and gene sets designed to target a set of genes that belong to a particular gene family or pathway. The website offers a user-friendly design center to select siRNA targets.

Genscript: Genscript offers various services including the design, manufacture and delivery of DNA vector-based siRNA, siRNA, siRNA cassettes, synthetic and recombinant peptides, and synthetic genes. For RNAi, Genscript specializes in siRNA cassettes, which they claim are more cost efficient than siRNA oligos. siRNA cassettes are PCR products which consist of a promoter (e.g. U6 and H1 promoter) and terminator sequence flanking a DNA insert encoding a hairpin siRNA. After transfected into cells, the DNA insert encoding a hairpin siRNA is expressed from the PCR product, and induces gene specific silencing. According to Genscript, siRNA cassettes cost only half of the corresponding synthetic siRNA oligos and the siRNA cassettes are delivered as DNA fragments, which are much more stable than RNA. Using the žsiRNA target finderÓ one can design custom siRNA cassettes.

Whitehead: The Whitehead RNAi design center consists of a quick and easy siRNA selection program. There are no explanations of RNAi or multiple options as in the other two websites. One merely logs in and submits a sequence for analysis.

Strengths:

Dharmacon: The Dharmacon design center was very easy to use. Obtaining results took about five minutes. There is ample emphasis on controls and extensive collection of control kits and products. In addition, the website  offers formats, quantities and prices to suit the needs and budgets of laboratories of different sizes.

Genscript: The žsiRNA target finderÓ for designing siRNAs is well explained and easy to use. The prices are listed on the website as you search.

Whitehead: If you want a quick and easy way to design siRNA oligos, this is your one-stop, no-frills website. 

Weaknesses:

Dharmacon: It can take a while to get used to all of the various options on the website, so figuring out exactly what part applies to you can be a little confusing.

Genscript: Does not offer synthetic siRNA oligos.

Whitehead: If you need more guidance or explanations, this website will not suffice

Comprehensiveness:

Dharmacon: Good.

Genscript: Good

Whitehead: Good

Timeliness:

Dharmacon: Last updated in February, 2004

Genscript: Recent information

Whitehead: Updated this year

Ease of Use:

Dharmacon: Easy

Genscript: Easy

Whitehead: Very easy

Responsiveness:

Dharmacon: The pages download quickly

Genscript: The pages download quickly

Whitehead: Very fast

Similar or Related Sites:

SVM for RNAi design

Drosophila RNAi screening center

Overall Evaluation:

Dharmacon: 4 stars

Genscript: 3 stars

Whitehead: 5 stars

Reviewer: Kat Cosmopoulos