Quality Control System in an Obstetrics and Gynecology Disease Biobank

To ensure that sample quality meets the requirements of experimental research, the gynecology and obstetrics biobank of the Nanjing Drum Tower hospital designed different quality control methods for relevant types of samples. A range of quality control procedures has been formulated.

The sample types were frozen tissue, paraffin-embedded tissue, optimal cutting temperature (OCT)-embedded tissue, plasma, buffy coat, serum, blood clots, and urine. Different categories of samples from a random selection of 1% of cases were analyzed for quality control experiments: (i) frozen tissue, buffy coat, and blood clots: RNA and DNA were extracted and the concentration, purity, and integrity were determined; (ii) paraffin-embedded tissue: morphological observations were made after hematoxylin-eosin staining and immunohistochemical detection of β-actin or CD10; (iii) OCT-embedded tissue: hematoxylin-eosin staining and immunofluorescence detection of β-actin; and (iv) frozen tissue samples derived from different organs of 18 fetal autopsy specimens with different cold ischemia times (CITs), 0-12 hours, 12-18 hours, 18-24 hours, and 24-48 hours, were chosen to study RNA quality. There is no universally recognized quality control index for plasma, serum, and urine, so the quality of samples was evaluated from feedback from the research projects in which the samples were used.

Currently, there are ∼2000 cases and 360,000 sample vials in the biobank. According to the experiments, (i) the concentration and purity of all nucleic acids of selected samples were qualified; (ii) for frozen tissues with a CIT ≤1 hour, using a qualified standard RNA quality number (RQN) ≥7, the qualification rate was 90%; (iii) frozen tissues with CIT between 1 and 18 hours, using a qualified standard RQN ≥5, the qualification rate was 61.1%; (iv) all of the paraffin-embedded tissues qualified for morphological observation; (v) the qualification rate of OCT-embedded tissue was 89%; and (vi) CIT had a great influence on the integrity of frozen tissue RNA. As the tissue CIT lengthened, the integrity of the RNA decreased. The RNA integrity parameters of different tissue types in the same specimen were significantly different.

A quality control system was constructed in an obstetrics and gynecology disease biobank with various types of diseases and abundant samples. Using specific quality control experiments for different types of samples was a reliable operating strategy that can be beneficial for providing qualified research resources. For birth defect autopsy specimens, the samples used for RNA research should have a CIT of at least <12 hours.