Strict precommitment

The precommitment hypothesis is considered throughout this review in its strict sense, thus as precommitment to synthesis of a single species of antibody molecules. It will be referred to as strict precommitment. Where it would be experimentally undistinguishable from precommitment to form a small number of different specificities, it will be referred to as quasi precommitment. 

Hence it can be concluded that the above experiments strongly support the precommitment hypothesis. It is not possible to distinguish between strict precommitment and quasi precommitment (see Introduction) because the method is insufficiently sensitive. 

Although all experiments are fully compatible with the idea of strict precommitment (e.g. precommitment to single specificity) this was not proven. Some methods by their nature cannot prove strict precommitment, and others are not sufficiently sensitive. Extreme restriction of the immunologic specificity and potentiality of a given cell was however proven beyond any doubt. 

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