Testing for AZoospermia Factor (AZF) deletions of the Y chromosome is a key component of the diagnostic workup of azoospermic and severely oligozoospermic men. This revision of the 2013 European Academy of Andrology (EAA) and EMQN CIC (previously known as the European Molecular Genetics Quality Network) laboratory guidelines summarizes recent clinically relevant advances and provides an update on the results of the external quality assessment program jointly offered by both organizations. A basic multiplex PCR reaction followed by a deletion extension analysis remains the gold-standard methodology to detect and correctly interpret AZF deletions. Recent data have led to an update of the sY84 reverse primer sequence, as well as to a refinement of what were previously considered as interchangeable border markers for AZFa and AZFb deletion breakpoints. More specifically, sY83 and sY143 are no longer recommended for the deletion extension analysis, leaving sY1064 and sY1192, respectively, as first-choice markers. Despite the transition, currently underway in several countries, toward a diagnosis based on certified kits, it should be noted that many of these commercial products are not recommended due to an unnecessarily high number of tested markers, and none of those currently available are, to the best of our knowledge, in accordance with the new first-choice markers for the deletion extension analysis. The gr/gr partial AZFc deletion remains a population-specific risk factor for impaired sperm production and a predisposing factor for testicular germ cell tumors. Testing for this deletion type is, as before, left at the discretion of the diagnostic labs and referring clinicians. Annual participation in an external quality control program is strongly encouraged, as the 22-year experience of the EMQN/EAA scheme clearly demonstrates a steep decline in diagnostic errors and an improvement in reporting practice.

With multiplex oligonucleotide ligation-PCR (MOL-PCR) different molecular markers can be simultaneously analysed in a single assay and high levels of multiplexing can be achieved in high-throughput format. As such, MOL-PCR is a convenient solution for microbial detection and identification assays where many markers should be analysed, including for routine further characterisation of an identified microbial pathogenic isolate. For an assay aimed at routine use, optimisation in terms of differentiation between positive and negative results and of cost and effort is indispensable. As MOL-PCR includes a multiplex ligation step, followed by a singleplex PCR and analysis with microspheres on a Luminex device, several parameters are accessible for optimisation. Although MOL-PCR performance may be influenced by the markers used in the assay and the targeted bacterial species, evaluation of the method of DNA isolation, the probe concentration, the amount of microspheres, and the concentration of reporter dye is advisable in the development of any MOL-PCR assay. Therefore, we here describe our observations made during the optimisation of a 20-plex MOL-PCR assay for subtyping of Salmonella Typhimurium with the aim to provide a possible workflow as guidance for the development and optimisation of a MOL-PCR assay for the characterisation of other microbial pathogens.

The 22q11.2 deletion is the most frequent interstitial deletion in humans and presents a wide phenotypic spectrum, with over 180 clinical manifestations described. Distinct studies have detected frequencies of the deletion ranging from 0 % to 75 %, depending on the studied population and selection criteria adopted. Due to the lack of consensus in this matter, several studies have been conducted aiming to define which patients would be eligible for screening; however, the issue is still up for debate. In order to contribute to the delineation of possible clinical and dysmorphologic guidelines to optimize decision making in the clinical setting, 194 individuals with variable features of the 22q11.2 deletion syndromes (22q11.2DS) were evaluated. Group I, clinical suspicion of 22q11.2DS with palatal anomalies; Group II, clinical suspicion without palatal anomalies; Group III, cardiac malformations associated with the 22q11.2DS; and Group IV, juvenile-onset schizophrenia. Multiplex ligation-dependent probe amplification was used for screening the 22q11.2 deletion, which was detected in 45 patients (23.2 %), distributed as such: Group I, 35/101 (34.7 %); Group II, 4/18 (22.2 %); Group III, 6/52 (11.5 %); and Group IV, 0/23 (0 %). Clinical data were analyzed by frequency distribution and statistically. Based on the present results and on the review of the literature, we propose a set of guidelines for screening patients with distinct manifestations of the 22q11.2DS in order to maximize resources. In addition, we report the dysmorphic features which we found to be statistically correlated with the presence of the 22q11.2DS.

A consensus multiplex real-time PCR test (PT13-RT) for the oncogenic human papillomavirus (HPV) types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 and 66 is described. The test targets the L1 gene. Analytical sensitivity is between 4 and 400 GU (genomic units) in the presence of 500 ng of human DNA, corresponding to 75,000 human cells. HPV types are grouped into multiplex groups of 3 or 4 resulting in the use of 4 wells per sample and permitting up to 24 samples per run (including controls) in a standard 96-well real-time PCR instrument. False negative results are avoided by (a) measuring sample DNA concentration to control that sufficient cellular material is present and (b) including HPV type 6 as a homologous internal control in order to detect PCR inhibition or competition from other (non-oncogenic) HPV types. Analysis time from refrigerator to report is 8 h, including 2.5 h hands-on time. Relative to the HC2 test, the sensitivity and specificity were respectively 98% and 83%, the lower specificity being attributable to the higher analytical sensitivity of PT13-RT. To assess type determination comparison was made with a reversed line-blot test. Type concordance was high (κ=0.79) with discrepancies occurring mostly in multiple-positive samples.

PCR-based immunoglobulin (Ig)/T-cell receptor (TCR) clonality testing in suspected lymphoproliferations has largely been standardized and has consequently become technically feasible in a routine diagnostic setting. Standardization of the pre-analytical and post-analytical phases is now essential to prevent misinterpretation and incorrect conclusions derived from clonality data. As clonality testing is not a quantitative assay, but rather concerns recognition of molecular patterns, guidelines for reliable interpretation and reporting are mandatory. Here, the EuroClonality (BIOMED-2) consortium summarizes important pre- and post-analytical aspects of clonality testing, provides guidelines for interpretation of clonality testing results, and presents a uniform way to report the results of the Ig/TCR assays. Starting from an immunobiological concept, two levels to report Ig/TCR profiles are discerned: the technical description of individual (multiplex) PCR reactions and the overall molecular conclusion for B and T cells. Collectively, the EuroClonality (BIOMED-2) guidelines and consensus reporting system should help to improve the general performance level of clonality assessment and interpretation, which will directly impact on routine clinical management (standardized best-practice) in patients with suspected lymphoproliferations.

OBJECTIVE: The clinical applications of in vitro manipulated cultured cells and their precursors are often made use of in therapeutic trials. However, tissue cultures can be easily contaminated by the ubiquitous Mollicutes micro-organisms, which can cause various and severe alterations in cellular function. Thus methods able to detect and trace Mollicutes impurities contaminating cell cultures are required before starting any attempt to grow cells under good manufacturing practice (GMP) conditions.
METHODS: We developed a multiplex quantitative polymerase chain reaction (qPCR) assay specific for the 16S-23S rRNA intergenic spacer regions, for the Tuf and P1 cytoadhesin genes, able to detect contaminant Mollicutes species in a single tube reaction. The system was validated by analyzing different cell lines and the positive samples were confirmed by 16S and P1 cytoadhesin gene dideoxy sequencing.
RESULTS: Our multiplex qPCR detection system was able to reach a sensitivity, specificity and robustness comparable with the culture and the indicator cell culture method, as required by the European Pharmacopoeia guidelines.
CONCLUSIONS: We have developed a multiplex qPCR method, validated following International Conference on Harmonization (ICH) guidelines, as a qualitative limit test for impurities, assessing the validation characteristics of limit of detection and specificity. It also follows the European Pharmacopoeia guidelines and Food and Drug Administration (FDA) requirements.

Forensic analysis of low template (LT) DNA mixtures is particularly complicated when (1) LT components concur with high template components, (2) more than three contributors are present, or (3) contributors are related. In this study, we generated a set of such complex LT mixtures and examined two methods to assist in DNA profile analysis and interpretation: the \"n/2\" consensus method (Benschop et al. 2011) and the pool profile approach. N/2 consensus profiles include alleles that are reproducibly amplified in at least half of the replications. Pool profiles are generated by injecting a blend of independently amplified PCR products on a capillary electrophoresis instrument. Both approaches resulted in a similar increase in the percentage of detected alleles compared to individual profiles, and both rarely included drop-in alleles in case mixtures of pristine DNAs were used. Interestingly, the consensus and the pool profiles often showed differences for the actual alleles detected for the LT component(s). We estimated the number of contributors using different methods. Better approximations were obtained with data in the consensus and pool profiles compared to the data of the individual profiles. Consensus profiles contain allele calls only, while pool profiles consist of both allele calls and peak height information, which can be of use in (statistical) profile analysis. All advantages and limitations of the various types of profiles were assessed, and based on the results we infer that both consensus and pool profiles (or a combination thereof) are helpful in the interpretation of complex LT DNA mixtures.