Automated PCR setup for forensic casework samples using the Normalization Wizard and PCR Setup robotic methods

Human genome, pharmaceutical and research laboratories have long enjoyed the application of robotics to performing repetitive laboratory tasks. However, the utilization of robotics in forensic laboratories for processing casework samples is relatively new and poses particular challenges. Since the quantity and quality (a mixture versus a single source sample, the level of degradation, the presence of PCR inhibitors) of the DNA contained within a casework sample is unknown, particular attention must be paid to procedural susceptibility to contamination, as well as DNA yield, especially as it pertains to samples with little biological material. The Virginia Department of Forensic Science (VDFS) has successfully automated forensic casework DNA extraction utilizing the DNA IQ(trade mark) System in conjunction with the Biomek 2000 Automation Workstation. Human DNA quantitation is also performed in a near complete automated fashion utilizing the AluQuant Human DNA Quantitation System and the Biomek 2000 Automation Workstation. Recently, the PCR setup for casework samples has been automated, employing the Biomek 2000 Automation Workstation and Normalization Wizard, Genetic Identity version, which utilizes the quantitation data, imported into the software, to create a customized automated method for DNA dilution, unique to that plate of DNA samples. The PCR Setup software method, used in conjunction with the Normalization Wizard method and written for the Biomek 2000, functions to mix the diluted DNA samples, transfer the PCR master mix, and transfer the diluted DNA samples to PCR amplification tubes. Once the process is complete, the DNA extracts, still on the deck of the robot in PCR amplification strip tubes, are transferred to pre-labeled 1.5 mL tubes for long-term storage using an automated method. The automation of these steps in the process of forensic DNA casework analysis has been accomplished by performing extensive optimization, validation and testing of the software methods.

A case report of severe external resorption

External root resorption is a multifactorial process with many causes. Except for transient surface resorption, it is usually considered an irreversible process. Treatment can arrest or retard the resorptive process. Many factors that have been associated with this process include physiologic resorption, local factors, systemic conditions, and idiopathic resorption. This case report documents a 29-year-old white male who suffered a motor vehicle accident and dental trauma nine years ago. The accident resulted in the lateral displacement of the maxillary right canine. The maxillary right lateral incisor, right central incisor and left central incisors were avulsed. The right central incisor was never recovered from the accident site. The other teeth were replanted 90 minutes after the accident and rigidly splinted for six months. They then received root canal treatment, approximately one month after the splint was removed (seven months from time of the trauma). On annual examination, the patient complained of a loose maxillary fixed prosthesis. He was diagnosed with severe external resorption on the right lateral and left central incisors, and severe external replacement resorption on the right canine. This case report reviews the current trends in the treatment of avulsed teeth and the resorptive process.