Immunoaffinity chromatography is a general term that covers a range of techniques the use of which is now widespread. Often these are based upon the use of antibodies to a speciRc target molecule or macro-molecule immobilized on some form of support (Figure 1). This is then used to separate or isolate the target molecule (or molecules of a similar structure) from a matrix in order to purify it for some subsequent purpose. Alternatively, immunoafRnity chromatography can be used to isolate antibodies by immobilizing the antigen, and indeed the Rrst example of the use of the technique can be traced back to the pioneering work of Campbell et al. who, in 1951, immobilized bovine serum albumin to a de-rivatized cellulose in order to purify antibodies that had been raised to it (Figure 2). These immunolo-gically-based methods include in addition immuno-afRnity precipitation, immunoafRnity adsorption and immunoafRnity extraction. Indeed the use of the term 'chromatography' is perhaps something of a misnomer as the technique often corresponds more to the online extraction of the target molecule onto the sorbent. Following extraction, a wash step is used to remove unwanted material followed by the recovery of the desired molecule with a strong eluent. It could thus be argued that in many applications immunoaf-Rnity chromatography is simply immunoafRnity extraction in a column format. The term 'immunoaf-Rnity chromatography' is however, widely used and understood by its practitioners.

Figure 1 Stationary phase with antibodies bound, only the antigen to which the antibodies were raised is retained. Other molecules pass through with little or no retention.
Figure 2 Stationary phase with antigen bound. Only antibodies to the antigen are retained.

Two, essentially different, types of applications of affinity chromatography can be distinguished. Thus there are those applications where isolation is with the intention of analysis (e.g. pesticides from water or drugs from blood plasma). Alternatively, immunoaf-finity chromatography is used for preparative purposes and the latter is often used for the isolation of high-value proteins in the biotechnology industry.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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