Abstract: The differential expression and subcellular localization of single-cell proteins are closely related to the physiological state and pathological mechanisms of the body. The development of single-cell protein in situ imaging methods provides powerful tools for spatial single-cell proteomics research and single-cell protein profiling. This article summarizes the single-cell protein imaging methods developed in recent years, including the circulating immunofluorescence imaging methods based on ordered multi-round antibody incubation, mass spectrometry imaging based on metal element labeled antibodies, fluorescence imaging based on DNA-barcoded antibody, gene encoded fluorescence protein imaging and spectral imaging based on Raman spectroscopy or X-ray spectroscopy, with brief explanation of the imaging principles of these methods. It focuses on the multiple performance, imaging resolution and signal amplification performance of these methods, and analyzes their application characteristics in practical scientific research and clinical work, in the hope of providing some reference for the development of more revolutionary single-cell imaging methods, and promoting the development of biomedical and precision medicine.

Bioluminescence is a widespread phenomenon in nature, and luminescent organisms can be found both on land and in the ocean. Among them, luciferase based bioluminescence systems have been widely studied, inspiring the exploration of genetic and epigenetic aspects and the development of a series of related assays for in vivo and in vitro studies. This paper summarizes the recent developments of luciferase based bioluminescence assays in terms of bioluminescence systems, types of luciferases, and the development and application of luciferase bioluminescence assays.

Gene editing tools with nucleases as the main component have now implemented programmable targeted mutagenesis or insertion or deletion of mammalian genomes.From zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), CRISPR/Cas system to safer and more accurate Cas9 fusion protein gene editing tools and other nuclease gene editing tools, this paper systematically describes the development and evolution of gene editing, with detailed introduction to the development and optimization of next-generation gene editing tools, and a prospect of the clinical application of and challenges for gene editing tools.

The corona virus disease 2019 (COVID-19) caused by the new coronavirus (SARS-CoV-2) has spread rapidly around the world,posing a serious threat to the public"s health. As of September 30,2020,the number of infected people in the world has reached 33 million,causing more than 1 million deaths. Normalized nucleic acid detection methods based on lab have long turnaround time and high cost. Therefore,there is an urgent need to develop a convenient method to detect SARS-CoV-2,so as to achieve rapid testing and timely control of the epidemic when resources are limited.This review summarizes the point-of-care testing (POCT) methods developed for SARS-CoV-2 in terms of extraction,amplification and detection,and briefly introduces commercial POCT instruments that integrate these three steps,in order to provide references for emergency response and rapid deployment of COVID-19 and other emerging infectious diseases.

Objective To explore the feasibility and clinical effect of laparoscopic radical cystectomy with intracorporeal Xing's orthotopic neobladder.Methods Forty-one patients who underwent laparoscopic radical cystectomy with intracorporeal Xing's orthotopic neobladder from July 2013 to August 2019.There were 31 cases performed in Beijing Chaoyang hospital and 10 cases in National Cancer Center.Mean age was 59 (range 44-78) years,mean BMI was 25.3 (range 20.1-34.7) kg/m2,and mean CCI was 3 (range 2-6).No urethral stricture or urinary incontinence was found by preoperative examination.No distant metastasis was identified by bone scans,chest X-ray and sonography.Cystoscopy or TURBT was performed on all patients and biopsy was taken to confirm the diagnosis.Preoperative pathology showed 30 cases (73.2％) of MIBC,9 cases of NMIBC (22.0％) and 2 cases (4.9％) of in-situ cancer.Laparoscopic radical cystectomy and lymphadenectomy were performed under general anesthesia.Urinary diversion was completed in the peritoneal cavity,by intercepting the terminal ileum about 60 cm,and taking the proximal ileum 10 cm as input loop on the right side with proximal to distal way,and the middle 40 cm ileum was detubated.After u-shaped suture,the ileum was folded back and stitched into a sphere building a novd orthotopic neobladder with bilateral isoperistaltic afferent limbs.The prognosis of perioperative data and postoperative satisfaction regarding continence were analyzed,continence was defined as 0-1 pad/day.The 41 patients were divided into two groups to compare the difference in term of operation time and blood loss between the first 21 patients and the last 20 patients.Results Mean total operative time was 324.9 mins (range 210-480) mins,and mean estimated blood loss was 177.6(range 50-700) ml.There were significant statistical differences in term of total operation time,construction time and blood loss between the first 21 patients and the next 20 patients (P ＜ 0.05).Postoperative pathological results were urothelial carcinoma in 40 cases (2 in situ carcinoma) and small cell carcinoma in 1 case.Mean number of dissected lymph nodes was 19 (range 11-58),with 7 cases(17.1％)of positive lymph nodes,and 3 cases(7.3％) had positive surgical margin.At a mean follow up of 17.6 (range 2-64) months,36 patients (87.8％) survived,including 2 patients (4.9％) with metastasis and 1 patient (2.4％) with recurrence,and 5 cases (12.2％)died.All patients were able to urinate without catheterization.Thirty-seven patients (90.2％) were satisfied with voiding control during the daytime (0-1 urinal pad),and 29 patients (70.7％) were satisfied with voiding control at nighttime (0-1 urinal pad) by the follow-up 12 months after the operation.Conclusions Total laparoscopic radical cystectomy combined with Xing's orthotopic ileum neobladder is a simple method with fewer postoperative complications and a satisfactory continence rate.

There are significant individual differences in the antiplatelet effects of aspirin.Three single nucleotide polymorphisms (SNPs),rs5918,rs12041331 and rs730012,are reported to significantly correlate with the efficacy and side effects of aspirin.In the present study,the genotyping method of the three SNPs was established based on the combination of polymerase chain reaction and pyrosequencing technology.Amplification and sequencing primers were designed independently;the amplification conditions were optimized to amplify the three SNPs in the same condition.The sensitivity of the method was detected using original genome DNA at different concentrations.In order to testify the accuracy of the method,the proposed method and Sanger sequencing technology were both used to genotype the three SNPs in 20 blood samples.The results demonstrated that the genotyping method of aspirin-related SNPs was successfully established,with the detection limit being as low as 0.4 ng genome DNA.The genotype results of 20 samples by the proposed method were exactly the same as that of Sanger sequencing.It is evident that the proposed method is sensitive and accurate.

Objective The NDRG4 gene methylation in stool is a candidate biomarker for non?invasive diagnosis of colorectal cancer. However, the traditional methods for methylation detection could not be well applied to stool samples due to the low sensitivity and low specificity. The aim of this study was to develop a highly sensitive and specific method for quantifying the methylated NDRG4 gene in stools. Methods Forty one stool samples were collected from 12 colorectal cancer patients, 4 adenoma patients and 25 nor?mal persons. The invasive reaction was combined with real?time PCR and the relative quantification was performed by 2-ΔCT method to develop the highly sensitive and specific methylated DNA detection method, which was used for detecting NDRG4 methylation levels in 41 of stool samples. Results The sensitivity of the method was as low as 10 copies of methylated NDRG4 gene fragments. The specificity was high enough to distinguish 0.01% of methylated fragments from un?methylated fragments and 105 copies of unmethylated NDRG4 fragments gave noamplification signals. The detection results from 41 of stool samples showed that detection rate of the NDRG4 gene in stool from adenoma and colorectal cancer groups had a significant difference comparing to that from the normal group. Conclusion The 2-ΔCT method could accurately quantify the methylation levels of the NDRG4 gene in stool samples, and provide an efficient tool for non?invasive colorectal cancer detection.

Pyrosequencing is one of the important genetic polymorphism detection methods currently, but the complicated pretreatment procedure limits its application in clinical test. To simplify the whole process of pyrosequencing, on the basis of the linear_after_the_exponential_polymerase chain reaction ( LATE_PCR) , we improved the primer design method of LATE_PCR, increased the length and the concentration of the excess primer, applied direct amplification technology with whole blood, and established a whole blood_imLATE_PCR method based on common rTaq polymerase and “HpH Buffer” ( High pH buffer ) . The amplification system was optimized, and the influences of blood anticoagulant and the amount of whole blood template were investigated. The single stranded template for the pyrosequencing was obtained by PCR amplification using a single tube in one_step process, and the alcohol dehydrogenase gene polymorphisms of 24 clinical blood samples were then detected successfully. The results could be used to guide clinical individualized medication. The genotypes of ADH1B locus of 24 samples were 6 cases of AA homozygote, 14 cases of AG heterozygote, and 4 cases of GG homozygote. The genotypes of ADH1C were 20 cases of GG homozygote, 4 cases of AG heterozygote, and no cases of AA homozygote.

Proteins presence and differences of the expression level can clarify the physiological or pathological changes in organisms;so the quantitative detection of proteins is vital for disease mechanism research;diagnosis and prognosis evaluation.Traditional protein quantitation methods at the tissue level reflected the average protein expression in cells;but ignore the differences between individual cells.In contrast;approaches for quantitative detection at single-cell level can better reflect the differences.Recently;a number of approaches for such detec-tion have been proposed;including microfluidics;microwell-based technology;optical fiber nanobiosensor;activity-based probe technology and mass spectrometry.The principles;advantages and drawbacks of these approaches are briefly introduced in this review.

A method for the real-time polymerase chain reaction ( PCR ) coupled with high specific invader assay to detect single nucleotide polymorphism ( SNP) was established. To reduce the background signal, the amount of flap endonuclease 1 ( FEN1 enzyme ) and wild-type detection probe was optimized. Under the optimum conditions including 0. 05 μmo/L invasive oligonucleotide probe, 0. 125 μmol/L wild-type detection probe, 0. 5 μmol/L mutation detection probe, 0. 25 μmol/L each fluorescence resonance energy transfer (FRET) probe and 1. 5 U FEN1, the background signal of wild-type sample and mutation sample was dramatically decreased and the background interference to the detecting results was thus eliminated. A total of 21 cases of aldehyde dehydrogenase-2*2 ( ALDH2*2 ) , 19 cases of cytochrome p450 2 C19*2 ( CYP2 C19*2 ) and 19 cases of CYP2C19*3 were analyzed with the established method, and the genotypes of ALDH2*2 were 10 cases of GG homozygote, 8 cases of GA heterozygote and 3 cases of AA homozygote; the genotypes of CYP2C19*2 were 9 cases of GG homozygote, 8 cases of GA heterozygote and 2 cases of AA homozygote;and the genotypes of CYP2C19*3 were 18 cases of GG homozygote and 1 case of GA heterozygote. These results were consistent with those by pyrosequencing. The established method was specific, simple, short time-consuming and low cost, and could be used for the detection of SNP genotyping with non-polluting in single closed tube.