An investigation of PCR inhibition using Plexor(®) -based quantitative PCR and short tandem repeat amplification.

A common problem in forensic DNA typing is PCR inhibition resulting in allele dropout and peak imbalance. In this paper, we have utilized the Plexor(®) real-time PCR quantification kit to evaluate PCR inhibition. This is performed by adding increasing concentrations of various inhibitors and evaluating changes in melt curves and PCR amplification efficiencies. Inhibitors examined included calcium, humic acid, collagen, phenol, tannic acid, hematin, melanin, urea, bile salts, EDTA, and guanidinium thiocyanate. Results were plotted and modeled using mathematical simulations. In general, we found that PCR inhibitors that bind DNA affect melt curves and CT takeoff points while those that affect the Taq polymerase tend to affect the slope of the amplification curve. Mixed mode effects were also visible. Quantitative PCR results were then compared with subsequent STR amplification using the PowerPlex(®) 16 HS System. The overall results demonstrate that real-time PCR can be an effective method to evaluate PCR inhibition and predict its effects on subsequent STR amplifications.

An account of significant events influencing Australian breastfeeding practice over the last 40 years.

BACKGROUND: Low breastfeeding duration rates reflect the pain and distress experienced by many women who discontinue breastfeeding in the early weeks and months of life. This paper explores modern key historical events that have significantly influenced Australian breastfeeding education and practice. METHOD: Relevant literature reviewed from 1970 to 2010 identified key events that appear to have contributed to the decrease in Australian breastfeeding rates and the increase in women experiencing breastfeeding complications, particularly nipple pain and trauma. FINDINGS AND DISCUSSION: The rise in institutionalisation and medical intervention in labour and birth has also medicalised midwifery practice. Technocratic intrusion and institutionalised care is contributing to the separation of the mother and newborn at birth. Delayed mother-baby initiation of breastfeeding and interruption of the duration of the first, and subsequent breastfeeds, negatively affects the innate ability of the mother and newborn to establish and sustain breastfeeding. The 'pathologising' of breastfeeding that involve midwives teaching women complicated and unnatural breastfeeding techniques interfere with instinctive sensory and mammalian behaviours and further contributes to the high complication rates. CONCLUSION: Midwives are encouraged to reflect on their role as 'experts' in the breastfeeding process and give confidence to women so that they utilise their instinctive ability to breastfeed by self-determined techniques that encourage mammalian skills for newborn sustenance and survival.