Rapid Veterinary Diagnosis of Bovine Reproductive Infectious Diseases from Semen Using Paper-Origami DNA Microfluidics

Application of preserved boar semen for artificial insemination: Past, present and future challenges

Artificial insemination (AI) is now used for breeding more than 90% of the sows in most of the world's primary pork producing countries. Despite the advancement of methods to cryopreserve boar semen, frozen semen has not been routinely used on farms because of limited efficiency. Liquid semen on the other hand, with 1.5-3 billion sperm per dose preserved up to seven days in long-term extenders, is in common use and is largely responsible for the widespread use of AI. Breeding organizations have defined individual thresholds for useable semen at 60-80% for motility and bacterial load of 0-1000 CFU/mL. Improvement in preservation techniques for liquid semen and better education of producers has been responsible for the higher efficiency of pig breeding, as measured by conception rate and increased litter size, with a minimum number of sperm. The introduction of deep intrauterine AI and advances in breeding management have also been contributing factors. The present article reviews the worldwide application of preserved boar semen from past to present and delineates future challenges. Pathways to increase breeding efficiency are outlined. The reconciliation of AI with sustainable breeding strategies is increasingly important. In this sense, guidelines for the prudent use of antibiotics in semen extenders are proposed. More efficient and sustainable pig AI awaits the introduction of sex-sorted sperm into AI practice. Another critical milestone that needs to be achieved is the replacement of conventional antibiotics in extenders.

Paper-based microfluidics for DNA diagnostics of malaria in low resource underserved rural communities

Populations living in remote rural communities would benefit from rapid, highly sensitive molecular, DNA-based diagnostics to inform the correct and timely treatment of infectious diseases. Such information is also becoming increasingly relevant in global efforts for disease elimination, where the testing of asymptomatic patients is now seen as being important for the identification of disease reservoirs. However, healthcare workers face practical and logistical problems in the implementation of such tests, which often involve complex instrumentation and centralized laboratories. Here we describe innovations in paper microfluidics that enable low-cost, multiplexed DNA-based diagnostics for malaria, delivered, in a first-in-human study, in schools in rural Uganda.

Rapid, low-cost, species-specific diagnosis, based upon DNA testing, is becoming important in the treatment of patients with infectious diseases. Here, we demonstrate an innovation that uses origami to enable multiplexed, sensitive assays that rival polymerase chain reactions (PCR) laboratory assays and provide high-quality, fast precision diagnostics for malaria. The paper-based microfluidic technology proposed here combines vertical flow sample-processing steps, including paper folding for whole-blood sample preparation, with an isothermal amplification and a lateral flow detection, incorporating a simple visualization system. Studies were performed in village schools in Uganda with individual diagnoses being completed in <50 min (faster than the standard laboratory-based PCR). The tests, which enabled the diagnosis of malaria species in patients from a finger prick of whole blood, were both highly sensitive and specific, detecting malaria in 98% of infected individuals in a double-blind first-in-human study. Our method was more sensitive than other field-based, benchmark techniques, including optical microscopy and industry standard rapid immunodiagnostic tests, both performed by experienced local healthcare teams (which detected malaria in 86% and 83% of cases, respectively). All assays were independently validated using a real-time double-blinded reference PCR assay. We not only demonstrate that advanced, low-cost DNA-based sensors can be implemented in underserved communities at the point of need but also highlight the challenges associated with developing and implementing new diagnostic technologies in the field, without access to laboratories or infrastructure.

Sensing Cell Membrane Biophysical Properties for Detection of High Quality Human Oocytes

Oocyte quality plays a crucial role in the early development and implantation of the embryos, and consequently has a profound impact on the accomplishment of assisted reproductive technology (ART). A simple and efficient method for detecting high-quality human oocytes is urgently needed. However, the clinically used morphological method is time-consuming, subjective, and inaccurate. To this end, we propose a practical and effective approach for detecting high-quality oocytes via on-chip measurement of the oocyte membrane permeability. We found that oocytes can be divided into two subpopulations (high-quality versus poor-quality oocytes) according to their membrane permeability differences, and as was further confirmed by subsequent in vitro fertilization (IVF) and development experiments (the blastocyst rates of high-quality and poor-quality oocytes were 60% and 0%, respectively). This approach shows great potentials in improving the success of ART, including both the fertilization and development rates, and thus it may have wide applications in the clinic.