The specialization of clinical laboratories is a distinctive feature of the modern laboratory domain development. Specialized clinical laboratories investigate rare, poorly understood diseases and special types of pathology, which appears in mass-producing of the most complicated investigations. The main contributing factor to increasing number of specialized clinical laboratories can be considered a scientific progress aimed at rare diseases and pathogens studying, as well as developing promising diagnostic methods. Presence of special hygienic conditions also contributes to the clinical labs specialization. The study showed that information on the significance of the results obtained in specialized clinical laboratories is underestimated. This is manifested in the normative and information field gaps of narrow focus labs operation. In particular, there are no criteria for classifying laboratories as specialized. The methods for efficient utilization of expensive specialized laboratory services, including ordering tests patterns training and limitations of new diagnostic methods are absent. There are no procedures for financing specialized clinical labs (reimbursement for services) etc. At the same time, specialization of clinical laboratories is a promising direction of the laboratory domain development in the context of the transition to personalized medicine. This is due to high specialists’ competence, their interest in disease diagnostics (not just qualitative performance of tests) as well as their ability to influence the diagnostic process and development of therapeutic strategy. Specialized clinical laboratory by performing measurements at the highest available analytical level is able to function as expert laboratory with reference functions in the field of laboratory medicine. From the economic point of view, narrow profiling allows to take advantages of a niche market, which has a positive effect on the price and TAT of the performing tests. General laboratories that perform common tests do not fully possess these distinctive features, since they solve broader problems, and the improvement of the laboratory diagnostic process there is slower.