Tissue microarrays:a new positive control of immunohistochemical staining

Purpose To develop an efficient and convenient positive control of immunohistochemical staining. Methods 60 cases of different positive sections of immunohistochemical staining and their paraffin blocks were chosen. A tissue microarrays block with 0.6 mm in diameter tissue core was constructed by using the tissue microarrayer. After continuous cutting, 150 sections were obtained. The microarray contained 77 tissue cores, with a dimension of 0.8 cm×0.5 cm and a wide antigen profile. One section of tissue microarray was as a positive control on each slide of the patient tissue to undergo identical immunohistochemical procedures. Results During the immunohistochemical procedures, at least one of microarray cores presented positive and the others were as the negative control. Then, we had a definite contrast to interpret whether the tested tissue was positive or not. Conclusion Compared with conventional positive control, the microarray positive control is more efficient, scientific, simple and applicable.