As with the many competing PCR purification kits, the Real Biotech Corp (RBC) HiYield™ Gel/PCR DNA Extraction Kit is part of a range of nucleic acid purification products from Real Biotech Corporation. The kit is designed for the purification of DNA fragments from both agarose gel slices and also PCR reactions. In reality, the kit can be used to extract small to medium sized DNA fragments from most reaction types (for example, we have used these kits to purify DNA from end-fill reactions, enzymatic digestions, labeling reactions and so forth).
The RBC kit is similar to other products (such as those from Invitrogen, Qiagen, Promega, Eppendorf and others). The RBC kits are significantly less expensive and this is what initially attracted our attention. Probably as a result of the lower price, the quality of the printed material that is supplied with the kit is also lower. This is a minor point, though, as all the relevant information is included. The reagents work well and to a level that is similar to other kits. However, have found the Qiagen kits to be slightly more efficient.
The RBC kits quote a maximum yield of 30 ug, which is mid-range in manufacturer-quoted figures. Many manufacturers quote a maximum capacity of 20 ug, and a few quote a maximum of 40 ìg per column. However, it is rare that the columns are used at or even near their binding capacity, so we regard this as unimportant.
The technology used in this kit is based on the same basic method used by the vast majority of competing products. The kit utilizes the standard immobilized silica column format to bind the nucleic acids in conjunction with a chaotropic salt to inactivate any enzymes and/or host-cell proteins. After binding, a wash buffer is applied to remove salts. The DNA is then eluted using the ‘elution buffer’, which is, in fact, Tris-EDTA (TE) buffer. Most kits, though, supply just Tris buffer rather than TE. We regard the TE buffer as a disadvantage because the EDTA in the RBC kit can interfere with downstream reactions that rely on divalent cations. Of course, the elution buffer can be replaced with Tris buffer or distilled water.
Because of the common technological and methodological basis behind DNA purification kits, it is not surprising that the results from the RBC product are similar to that of others we have tested. We routinely obtain good yield and high purity products using this kit and they perform similarly in side-by-side testing with several competitors’ products when used for cloning, sequencing, enzymatic digestion, PCR and end-filling.