The present application relates to: (i) a sampler device for taking a sample of biological fluid, which comprises a capillary component, and a base rigidly connected to said capillary component and provided with a first connector capable of being reversibly attached in a leaktight manner to a second connector of a dispensing device; (ii) a dispensing device which also comprises means for transferring diluting fluid which open into said second connector. The application also relates to a biological analysis apparatus implementing the sampler and dispensing devices and to a method for sampling and dispensing a biological fluid.