he present invention refers to the examination of the endometrium. Analysis is performed through tests that utilize endometrial menstruation tissue (period tissue) which is collected to this purpose. The tests are carried out for the study of the composition of the sub-populations of lymphocytes in order to assess whether the endometrium is appropriate for the implantation and the preservation of the fetus. These tests are also carried out for the study of the presence of microorganisms on theendometrium and also for the study of the cellular composition of the period tissue. A tube is also described for use for the collection of menstruation tissue, which tube has certain special characteristics which facilitate the tests of the period tissue.
