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[Contribution to the problem of Arthrogryposis multiplex (author's transl)].

A case of Arthrogryposis multiplex appearing after birth and of no characteristical course is described. It is shown that in respect to existing works for diagnosis of Arthrogryposis multiplex the insufficiency of the hitherto existing valid diagnostic criterions is obvious. This especially because the pathogenesis of Arthrogryposis multiplex is unknown. Trying to look for the condition of the connective tissue of our patient, it was found that the collagen of skin shows a young matter of polymerisation and a nearly correlating electron microscopical picture.

Adult

Fluorescent multiplex linkage analysis and carrier detection for Duchenne/Becker muscular dystrophy.

We have developed a fast and accurate PCR-based linkage and carrier detection protocol for families of Duchenne muscular dystrophy (DMD)/Becker muscular dystrophy (BMD) patients with or without detectable deletions of the dystrophin gene, using fluorescent PCR products analyzed on an automated sequencer. When a deletion is found in the affected male DMD/BMD patient by standard multiplex PCR, fluorescently labeled primers specific for the deleted and nondeleted exon(s) are used to amplify the DNA of at-risk female relatives by using multiplex PCR at low cycle number (20 cycles). The products are then quantitatively analyzed on an automatic sequencer to determine whether they are heterozygous for the deletion and thus are carriers. As a confirmation of the deletion data, and in cases in which a deletion is not found in the proband, fluorescent multiplex PCR linkage is done by using four previously described polymorphic dinucleotide sequences. The four (CA)n repeats are located throughout the dystrophin gene, making the analysis highly informative and accurate. We present the successful application of this protocol in families who proved refractory to more traditional analyses.

DNA

SLB-msSIM: A Spectral Library-Based Multiplex Segmented SIM Platform for Single-Cell Proteomic Analysis.

Mass spectrometry (MS)-based single-cell proteomics, while highly challenging, offers unique potential for a wide range of applications to interrogate cellular heterogeneity, trajectories, and phenotypes at a functional level. We report here the development of the spectral library-based multiplex segmented selected ion monitoring (SLB-msSIM) method, a conceptually unique approach with significantly enhanced sensitivity and robustness for single-cell analysis. The single-cell MS data is acquired by a multiplex segmented selected ion monitoring (msSIM) technique, which sequentially applies multiple isolation cycles with the quadrupole using a wide isolation window in each cycle to accumulate and store precursor ions in the C-trap for a single scan in the Orbitrap. Proteomic identification is achieved through spectral matching using a well-defined spectral library. We applied the SLB-msSIM method to interrogate cellular heterogeneity in various pancreatic cancer cell lines, revealing common and distinct functional traits among PANC-1, MIA-PaCa2, AsPc-1, HPAF, and normal HPDE cells. Furthermore, for the first time, our novel data revealed the diverse cell trajectories of individual PANC-1 cells during the induction and reversal of epithelial-mesenchymal transition (EMT). Collectively, our results demonstrate that SLB-msSIM is a highly sensitive and robust platform, applicable to a wide range of instruments for single-cell proteomic studies. SUMMARY: We present the SLB-msSIM method, a conceptually unique approach in mass spectrometry-based single-cell proteomics that significantly enhances sensitivity and robustness. This innovative platform enables detailed analysis of the proteome landscape, capturing cellular heterogeneity, trajectories, and phenotypes at a single-cell resolution. Utilizing the SLB-msSIM technique, we identified both common and distinct functional traits among various pancreatic cancer cell lines and normal cells. Moreover, our study unveiled new insights into the diverse cell trajectories of individual cancer cells during the induction and reversal of epithelial-mesenchymal transition (EMT). In summary, the SLB-msSIM method offers a highly sensitive and robust platform for single-cell proteomic studies, with broad applicability across different instruments.

Single-Cell Analysis

High-Plex Tissue Imaging with Conventional Immunofluorescence Platforms and Open-Source Software via Iterative Bleaching Extends Multiplexity (IBEX).

Iterative bleaching extends multiplexity (IBEX) is an easy-to-use, highly multiplex immunofluorescent tissue imaging method that employs widely available microscopy platforms, commercial reagents, and open-source software. In this article, we describe how to implement this method in a laboratory that has minimal experience with immunohistochemistry.

Software

Improving quality control of microbial agri-inputs by confirming strain identity with an easy and low-cost PCR-multiplex: A study case with Azospirillum brasilense.

The first commercial product containing the Azospirillum brasilense elite strains Ab-V5 and Ab-V6 was launched in Brazil in 2009. These strains have demonstrated agronomic efficiency in grasses and in legume co-inoculation, accounting for approximately 43 million doses in 2024. Official identification of these strains is currently performed by rep-PCR, a reliable but time-consuming and laborious method. In this study, a multiplex PCR assay was developed for the simultaneous identification of Ab-V5 and Ab-V6 in a single reaction using strain-specific SNPs. Forward primers were designed so that the terminal nucleotide at the 3' end corresponded to a strain-specific SNP unique to each target strain. To further enhance specificity, artificial mismatches were introduced at the fourth nucleotide from the 3' end of the forward primers. SNPs were identified using Snippy based on genomic alignments between Ab-V5 and Ab-V6 and confirmed by local BLASTn against the genomes of other Azospirillum species. In the multiplex assay, simultaneous and specific amplification of both strains was observed in a single reaction, without non-specific amplification. Primer specificity was also experimentally evaluated against other A. brasilense strains (Ab-V1, Ab-V2, Ab-V4, Ab-V7, Ab-V8, and Sp7T), in silico against bacteria from different genera associated with agricultural inoculants, and in commercial inoculant samples containing Ab-V5 and Ab-V6. The results confirmed the high specificity of the primers for Ab-V5 and Ab-V6 and demonstrated that the assay was capable of identifying the strains in commercial inoculants. This assay facilitates inoculant quality control by enabling strain confirmation using a simple, rapid, and low-cost method.

Azospirillum

Enhancing Hemoglobin Bart's hydrops fetalis syndrome prevention: a single-tube multiplex real-time PCR assay for the comprehensive detection of four significant α0-thalassemia deletions (--SEA, --THAI, --CR, and --SA) found in Thailand.

BACKGROUND: Hemoglobin (Hb) Bart's hydrops fetalis is a major public health concern in Southeast Asia, particularly in Thailand. Current screening strategies target the two most common α0 -thalassemia deletions (--SEA and --THAI). METHOD: In this study, we developed a single-tube multiplex real-time PCR assay for the simultaneous detection of four clinically relevant α0-thalassemia deletions (--SEA, --THAI, --CR, and --SA). The assay was validated using 538 clinical samples with diverse thalassemia genotypes and compared against conventional gap-PCR as the reference method. Analytical performance, including sensitivity, specificity, and limit of detection (LOD), was evaluated. In addition, clinical utility was assessed in 22 prenatal diagnosis cases at risk of Hb Bart's hydrops fetalis. RESULTS: The study cohort demonstrated substantial genetic heterogeneity, comprising 43 distinct genotypes. The developed assay achieved 100% sensitivity and specificity for all targeted deletions, with complete concordance with gap-PCR results. No cross-reactivity was observed with α+-thalassemia. The assay demonstrated a high analytical sensitivity with a LOD of 9.76 × 10-3 ng per reaction. Whereas in prenatal diagnosis, all 22 fetal genotypes were accurately identified, including five cases of homozygous --SEA and one rare compound heterozygous --SEA/--CR fetus. CONCLUSIONS: This study presents a rapid, accurate, and cost-effective multiplex real-time PCR assay capable of detecting both common and rare α0-thalassemia deletions in a single reaction. The assay demonstrates strong potential for implementation in routine clinical laboratories and large-scale population screening, contributing to improved prevention and control of severe thalassemia syndromes in high-prevalence regions.

Humans

Rapid and accurate sepsis diagnostics via a novel probe-based multiplex real-time PCR system.

Sepsis is a critical clinical emergency that requires prompt diagnosis and intervention. Its prevalence has increased due to the aging population and increased antibiotic resistance. Early identification and the use of innovative technologies are crucial for improving patient outcomes. Modern methodologies are needed to minimize the turnaround time for diagnosis and improve outcomes. Rapid diagnostic tests and multiplex PCR are effective but have limitations in identifying a range of pathogens and target genes. Our study evaluated two novel probe-based multiplex real-time PCR systems: the SEPSI ID and SEPSI DR panels. These systems can quickly identify bacterial and fungal pathogens, alongside antibiotic resistance genes. The assays cover 29 microorganisms (gram-negative bacteria, gram-positive bacteria, yeast, and mold species), alongside 23 resistance genes and four virulence factors. A streamlined workflow uses 2 µL of broth from positive blood cultures (BCs) without nucleic acid extraction and provides results in approximately 1 h. We present the results from an evaluation of 228 BCs and 22 isolates previously characterized by whole-genome sequencing. In comparison to the reference methods, the SEPSI ID panel demonstrated a sensitivity of 96.88%, a specificity of 100%, and a PPV of 100%, whereas the SEPSI DR panel showed a sensitivity of 97.8%, a PPV of 89.7%, and a specificity of 96.7%. Both panels also identified additional pathogens and resistance-related targets not detected by conventional methods. This assay shows promise for rapidly and accurately diagnosing sepsis. Future studies should validate its performance in various clinical settings to enhance sepsis management and improve patient outcomes.IMPORTANCEWe present a new diagnostic method that enables the quick and precise identification of pathogens and resistance genes from positive blood cultures, eliminating the need for nucleic acid extraction. This technique can also be used on fresh pathogen cultures. It has the potential to greatly improve treatment protocols, leading to better patient outcomes, more responsible antibiotic use, and more efficient management of healthcare resources.

Humans

Development and epidemiological investigation of a TaqMan-based multiplex real-time quantitative PCR assay for simultaneous detection of five bovine viruses (BVDV, AKAV, BNoV, BEV, and BCoV).

INRODUCTION: Infectious diseases caused by bovine viral diarrhea virus (BVDV), Akabane virus (AKAV), bovine norovirus (BNoV), bovine enterovirus (BEV), and bovine coronavirus (BCoV) significantly threaten the cattle industry, resulting in substantial economic losses. These pathogens often present similar clinical signs, such as diarrhea, vomiting, and reproductive disorders in pregnant cattle, and frequent covert or mixed infections further complicate accurate diagnosis. Therefore, rapid, sensitive, and field‑deployable diagnostic methods are essential for effective disease surveillance and control in the cattle industry. METHODS: In this study, we report for the first time the establishment of a TaqMan‑based real‑time quantitative PCR (qPCR) assay that enables simultaneous detection of these five bovine viruses. Multiple sequence alignment of conserved genomic regions was performed, and virus‑specific primers and probes were designed and optimized using Beacon Designer 7 software. Subsequently, a TaqMan‑based multiplex real‑time qPCR assay was established for simultaneous detection of BVDV, AKAV, BNoV, BEV, and BCoV. The established detection method was applied to 200 clinical samples collected from 10 farms in multiple regions of Jilin Province. RESULTS: The results showed that the detection rates for BVDV, AKAV, BNoV, BEV, and BCoV were 33.50%, 0.50%, 4.50%, 7.50%, and 12.00%, respectively. Mixed infections were detected in 9 samples co‑infected with two of the five pathogens, with an overall mixed infection rate of 4.50%. Compared with conventional PCR, coincidence rates were 100% for BVDV, AKAV, BNoV, BEV, and BCoV. DISCUSSION: These findings indicate that the TaqMan multiplex real‑time qPCR assay developed here demonstrates favorable specificity, sensitivity, and reproducibility. This assay enables efficient detection and surveillance of bovine viruses, offering a reliable technical tool for the diagnosis and control of corresponding viral diseases in cattle.

Akabane virus (AKAV)

Case-of-the-month: perineuritis presenting as mononeuritis multiplex.

Perineuritis unassociated with other significant pathological changes is a rare finding. A patient is described with mild, non-insulin dependent diabetes mellitus who presented with the clinical picture of mononeuritis multiplex, and in whom perineuritis but no occlusive vascular disease was found on sural nerve biopsy. Treatment with prednisone and plasma exchange resulted in some improvement. We conclude that the focal perineuritis, rather than the diabetes, was responsible for the clinical picture mimicking mononeuritis multiplex. In conjunction with previous reports, this suggests that perineuritis may be a treatable neuropathy.

Aged

Further evidence that arthrogryposis multiplex congenita in the human sometimes is caused by an intrauterine vascular accident.

A 7 1/2-year-old girl with arthrogryposis multiplex congenita of the amyoplasia type in association with intestinal atresias, gastroschisis, Möbius anomaly, and hypoplasia of the pectoral, biceps, and deltoid muscles is described. Several combinations of these birth defects have been previously described. There is considerable evidence that gastroschisis, intestinal atresia, Poland sequence, and Möbius anomaly each has a vascular pathogenesis. Based on the associations seen in this child and past reports of more limited, similar cooccurrences, we suggest that arthrogryposis multiplex congenita may sometimes be caused by an intrauterine vascular catastrophe.

Abdominal Muscles

Screening for cystic fibrosis gene mutations by multiplex DNA amplification.

We have developed a simple rapid DNA screening test that allows us simultaneously to analyze seven CF mutations (delta F508, R347P, S549N, G551D, R553X, R334W, 444delA) that together account for about 60% of all CF mutations in the Italian population. It consists of three steps: multiplex polymerase chain reaction (PCR) amplification of exons 4, 7, 10 and 11; restriction endonuclease digestion of the PCR products; and vertical polyacrylamide gel electrophoresis analysis. We have used our multiplex assay for analyzing 15 CF chromosomes (non delta F508) and have found 3 cases of the R553X mutation; the latter have been confirmed by amplification and digestion of exon 11.

Amino Acid Sequence

Non-radioactive detection of the most common mutations in the cystic fibrosis transmembrane conductance regulator gene by multiplex allele-specific polymerase chain reaction.

A rapid, simple, nonradioactive method for detection of four common mutations causing cystic fibrosis (CF) has been developed combining multiplexing with allele-specific polymerase chain reaction amplification. This approach (MASPCR) provides an easy assay for direct genotyping of normal and mutant CF alleles in homozygotes and heterozygotes. The strategy involves multiplex PCR of exons 10, 11, and 21 within the cystic fibrosis transmembrane conductance regulator (CFTR) gene in a single reaction containing three common oligoprimers and either the four normal or four mutant oligos corresponding to the delta F508, G551D, G542X, and N1303K mutations. Primers are chosen so that the size of the four PCR products differ, thereby facilitating detection on agarose gels following amplification in the same reaction. Patient samples are primed with either four normal or four mutant oligo mixtures, and PCR products run in parallel on gels to detect band presence or absence. This approach provides a simple and potentially automated method for cost-effective population screening.

Alleles

Point mutations and polymorphisms in the human dystrophin gene identified in genomic DNA sequences amplified by multiplex PCR.

About one third of Duchenne muscular dystrophy (DMD) patients have no gross DNA rearrangements in the dystrophin gene detectable by Southern blot analysis or multiplex exon amplification. Presumably, in these cases, the deficiency is caused by minor structural lesions of the dystrophin gene. However, to date, only a single human DMD case has been described where a point mutation, producing a stop codon, accounts for the DMD phenotype. To screen for microheterogeneities in the dystrophin gene, we applied analysis by chemical mismatch cleavage to thirteen exons amplified in multiplex sets by the polymerase chain reaction. This analysis covers approximately 20% of the dystrophin-coding sequence. Sixty DMD patients without detectable deletions or duplications were investigated, leading to the identification of two point mutations and four polymorphisms with a frequency higher than 5%. Both point mutations are frameshift mutations in exons 12 and 48, respectively, and are closely followed by stop codons, thus explaining the functional deficiency of the dystrophin gene products in both patients.

Base Sequence

Genetic mapping of four dinucleotide repeat loci, DXS453, DXS458, DXS454, and DXS424, on the X chromosome using multiplex polymerase chain reaction.

Dinucleotide CA repeat sequences in the human genome have been shown to be highly polymorphic due to variation in the length of the repeat-containing segment. Therefore, these markers can serve as anchor loci in the construction of a high-resolution genetic map of the human genome. In this study, we improved the efficiency of typing dinucleotide repeats using multiplex polymerase chain reaction (PCR). Dinucleotide repeat sequences of four previously identified markers (DXS453, DXS458, DXS454, and DXS424) on the long arm of the X chromosome were simultaneously amplified in a single PCR reaction. This multiplex PCR was applied to genotype individuals from the 40 CEPH reference families, and the genotypic data were used to determine the map position of the four loci with respect to eight reference markers in the Xq region by linkage analysis.

Base Sequence

Fluorescence-based, multiplex allele-specific PCR (MASPCR) detection of the delta F508 deletion in the cystic fibrosis transmembrane conductance regulator (CFTR) gene.

Cystic fibrosis (CF) is a common genetic disorder in Caucasians, and in some populations 70% of cases are associated with a 3 base pair (bp) deletion (delta F508) in the CFTR gene. We have implemented a fluorescence-based, multiplex allele-specific polymerase chain reaction (MASPCR) assay for deletion of the delta F508 mutation. Different allele-specific fluorescently-tagged primers are used in the PCR reaction to distinguish between normal and delta F508 alleles. Fluorescent PCR products are then visualized in a single lane on an agarose gel following electrophoresis combined with real-time multicolour fluorescence detection. The approach simplifies diagnosis of the most common mutation in the CFTR gene, and holds promise for a multiplex allele-specific, fluorescence-tagged gene amplification strategy for detection of additional CF mutations which may result in more cost-effective testing without increasing the risk of missed or erroneous diagnoses.

Alleles

A dual-dimensional CRISPR toolkit enables one-step high-efficiency multiplex genome editing in Komagataella phaffii.

Against the backdrop of green biomanufacturing, engineering methanol-utilizing Komagataella phaffii (K. phaffii) represents an effective strategy to expand the one carbon (C1) product profile and speed up the industrialization of C1-based bioeconomy. To address the technical challenges of low efficiency and cumbersome experimental procedures for multiplex gene editing and precise large-fragment integration during the reconstruction of complex metabolic pathways in K. phaffii, this study established a CRISPR toolkit - Efficient Multi-Gene Editing System 3.0 (EMGES 3.0) - which enabled one-step large-fragment integration coupled with multiplex gene knockout. EMGES 3.0 was constructed through the synergistic optimization of a repair-engineered chassis and an episomal CRISPR vector. For chassis engineering, five DNA repair modules: Δlig4 (DNA Ligase IV, non-homologous end joining end ligation), ppMRE11(The endogenous MRE11 gene from Pichia pastoris) overexpression (The Meiotic Recombination 11, DNA double-strand break end resection), Δrad9 (Radiation-Sensitive 9, DNA damage checkpoint regulation), Δmph1 (Mutator Phenotype Helicase 1, improvement of homologous recombinant strand extension), and PapRecT-PaSSB co-expression (stabilization of recombination intermediates) were integrated to generate the highly recombinogenic strain Y09. For vector engineering, cenARS was replaced by panARS and the endogenous promoter PGAP was employed to drive the double hammerhead ribozyme-single guide RNA-hepatitis delta virus ribozyme (double HH-sgRNA-HDV: dHgH)-mediated sgRNA expression, yielding the optimized vector Nov_pGAP_panARS_pLAT1_Cas9. These two features on K. phaffii together enhanced the EMGES 3.0 to a higher standard of transformation rate and editing efficiency. According to our results, EMGES 3.0 achieved dual-functional gene knockout efficiencies between 76.6% and 100%. For insertion of medium-long fragments (>4.5 kb), the efficiency achieved 93.3%. In addition, the one-step integration of ultra-long fragments (>16 kb) achieved 14.8%, which was reported for the first time. Furthermore, the efficiency of simultaneous long-fragment integration at three neutral loci reached 38.4% (>15 kb). We applied the system for one-step production of free fatty acids (FFAs, yield: 5.82 ∼ 7.30 mg/L/OD600) and resveratrol (yield: 1.14 ∼ 1.28 mg/L) using methanol as the sole carbon source. EMGES 3.0 provides a robust technical foundation for complex compounds biosynthesis and high-yield industrial strains, while also advancing K. phaffii as an industrial synthetic biology chassis for efficient C1 utilization.

CRISPR-Cas Systems

Tribus: semi-automated discovery of cell identities and phenotypes from multiplexed imaging and proteomic data.

MOTIVATION: Multiplexed imaging and single-cell analysis are increasingly applied to investigate the tissue spatial ecosystems in cancer and other complex diseases. Accurate single-cell phenotyping based on marker combinations is a critical but challenging task due to (i) low reproducibility across experiments with manual thresholding, and, (ii) labor-intensive ground-truth expert annotation required for learning-based methods. RESULTS: We developed Tribus, an interactive knowledge-based classifier for multiplexed images and proteomic datasets that avoids hard-set thresholds and manual labeling. We demonstrated that Tribus recovers fine-grained cell types, matching the gold standard annotations by human experts. Additionally, Tribus can target ambiguous populations and discover phenotypically distinct cell subtypes. Through benchmarking against three similar methods in four public datasets with ground truth labels, we show that Tribus outperforms other methods in accuracy and computational efficiency, reducing runtime by an order of magnitude. Finally, we demonstrate the performance of Tribus in rapid and precise cell phenotyping with two large in-house whole-slide imaging datasets. AVAILABILITY AND IMPLEMENTATION: Tribus is available at https://github.com/farkkilab/tribus as an open-source Python package.

Proteomics

HyperCas12a enables multiplexed CRISPRi screens.

Interactions between multiple genes or cis-regulatory elements (CREs) underlie a wide range of biological processes in both health and disease. High-throughput screens using dCas9 fused to epigenome editing domains have allowed researchers to assess the impact of activation or repression of both coding and non-coding genomic regions on a phenotype of interest, but assessment of genetic interactions between those elements has been limited to pairs. Here, we combine a hyper-efficient version of Lachnospiraceae bacterium dCas12a (dHyperLbCas12a) with RNA Polymerase II expression of long CRISPR RNA (crRNA) arrays to enable efficient highly-multiplexed epigenome editing. We demonstrate that this system is compatible with several activation and repression domains, including the P300 histone acetyltransferase domain and SIN3A interacting domain (SID). We further show that the system can be used in cultured primary immune cells and to drive differentiation of induced pluripotent stem cells. We also developed new approaches to use the dCas12a platform for simultaneous activation and repression from a single crRNA array via co-expression of multiple dCas12a orthologues. Lastly, we demonstrate that the dHyperLbCas12a effectors are highly effective for multiple modalities of high-throughput screens, namely proliferation screens and screens to dissect the independent and combinatorial contributions of CREs on gene expression. The tools and methods introduced here create new possibilities for highly multiplexed control of gene expression in a wide variety of biological systems.

Journal Article