Pandora box of BCA assay. Investigation of the accuracy and linearity of the microplate bicinchoninic protein assay: Analytical challenges and method modifications to minimize systematic errors

Bicinchoninic colorimetric assay is very widely used for total protein quantitative analysis. We report that bicinchoninic (BCA) total protein assay linearity range and the assay sensitivity are counterbalancing factors. BCA assay true linear range may be considerably narrower than the manufacturer’s advertised 20-2000 μg/ml and therefore the choice of the assay calibration range should not solely be dictated by the general recommendations of the user guide, but by the test specific needs and subsequent assay quality control.
Expanding the BCA assay range up to 2000 μg/ml comes together with unavoidable heavy negative biases at low protein concentrations. The negative bias at low protein concentration only exacerbates with longer incubation time and/or increased sample to working reagent ratio. To minimize the lack of accuracy at low protein concentration of a wide range BCA assay, we proposing an alternative approach: a two-step incubation and calibration. With a minimum of extra work, the two-step incubation/calibration approach is devoid of the standard BCA workflow disadvantages and biases.

Role of Trichoderma as a biocontrol agent (BCA) of phytoparasitic nematodes and plant growth inducer

Nematodes as plant pathogens adversely affect food, fiber, and biofuels production by causing plant diseases. A variety of chemical nematicides are being applied to soil, seeds, or foliage with a goal of disease prevention. Despite the proven efficacy of these chemicals against plant-parasitic nematodes, factors like prolonged residual toxicity to human health, environmental pollution, and the risk of resistance development can’t be neglected.
Due to these reasons, many chemicals are being banned continuously or delimited in the crop production system. Alternatively, the need for long-term strategies and integrative approaches to control plant diseases is inevitable. Trichoderma spp. are widely used in agriculture as biological control agents (BCA). To our knowledge, either very little or no information available on the most recent developments regarding Trichoderma-mediated biological control of plant-parasitic nematodes. This review summarizes the recent advances in using Trichoderma as BCA and plant growth regulator with a special focus on plant-parasitic nematodes.

IL-16 and BCA-1 Serum Levels Are Associated with Disease Severity of C. difficile Infection

Clostridioides difficile infection (CDI) is associated with a high risk for complications and death, which requires identifying severe patients and treating them accordingly. We examined the serum level of six cytokines and chemokines (IL-16, IL-21, IL-23, IL-33, BCA-1, TRAIL) and investigated the association between them and patients’ disease severity. Concentrations of six cytokines and chemokines were measured using the MILLIPLEX®MAP kit (Billerica, MA, USA) in serum samples attained from CDI patients within 24-48 h after laboratory confirmation of C. difficile presence. Demographic and clinical data were collected from medical records.
The disease severity score was determined according to guidelines of the “Society for Healthcare Epidemiology of America and the Infectious Diseases Society of America” (SHEA-IDSA). Out of 54 patients, 20 (37%) had mild to moderate disease and 34 (63%) had severe disease. IL-16 (p = 0.005) and BCA-1 (p = 0.012) were associated with a more severe disease. In conclusion, IL-16 and BCA-1, along with other cytokines and chemokines, may serve as biomarkers for the early prediction of CDI severity in the future. An improved and more accessible assessment of CDI severity will contribute to the adjustment of the medical treatment, which will lead to a better patient outcome.

Middle Meningeal Artery Embolization Using Combined Particle Embolization and nBCA with the Dextrose 5% in Water Push Technique for Chronic Subdural Hematomas: A Prospective Safety and Feasibility Study

Background and purpose: Embolization of the middle meningeal artery for treatment of refractory or recurrent chronic subdural hematomas has gained momentum during the past few years. Little has been reported on the use of the n-BCA liquid embolic system for middle meningeal artery embolization. We present the technical feasibility of using diluted n-BCA for middle meningeal artery embolization.
Materials and methods: We sought to examine the safety and technical feasibility of the diluted n-BCA liquid embolic system for middle meningeal artery embolization. Patients with chronic refractory or recurrent subdural hematomas were prospectively enrolled from September 2019 to June 2020. The primary outcome was the safety and technical feasibility of the use of diluted n-BCA for embolization of the middle meningeal artery. The secondary end point was the efficacy in reducing hematoma volume.
Results: A total of 16 patients were prospectively enrolled. Concomitant burr-hole craniotomies were performed in 12 of the 16 patients. Two patients required an operation following middle meningeal artery embolization for persistent symptoms. The primary end point was met in 100% of cases in which there were no intra- or postprocedural complications. Distal penetration of the middle meningeal artery branches was achieved in all the enrolled cases. A 7-day post-middle meningeal artery embolization follow-up head CT demonstrated improvement (>50% reduction in subdural hematoma volume) in 9/15 (60%) patients, with 6/15 (40%) showing an unchanged or stable subdural hematoma. At day 21, available CT scans demonstrated substantial further improvement (>75% reduction in subdural hematoma volume).
Conclusions: Embolization of the middle meningeal artery using diluted n-BCA and ethiodized oil (1:6) is safe and feasible from a technical standpoint. The use of a dextrose 5% bolus improves distal penetration of the glue.

Pre-diluted BSA (bovine serum albumin) standards (1 set) for BCA Optima Protein Assay kit

BCA-BSA-1 1 pk 196.8 EUR

Pre-diluted BSA (bovine serum albumin) standards (750 ug/ml) for BCA Optima Protein Assay kit

BCA-BSA-750 1 ml 270 EUR


HY-15908 500mg 129.6 EUR

Pre-diluted BSA (bovine serum albumin) standards (250, 125, 62.5, 31.25, and 0.0 ug/ml) for BCA Optima Protein Assay kit

BCA-BSA-2 1 pk 196.8 EUR

Pre-diluted BGG (bovine gamma globulin) standards (1 set: 2000, 1000, 500, 125, 62.5, 31.25, and 0 ng/ml BGG) for BCA Optima Protein Assay kit

BCA-BGG-1 1 pk 196.8 EUR

BCA Reagent, 16ML

C144-16ML 16ML 195.6 EUR

BCA Enhancer, 320UL

C145-320UL 320UL 195.6 EUR

BCA disodium salt

2810-100G each 1038 EUR

BCA disodium salt

2810-1G each 144 EUR

BCA disodium salt

2810-500G each 3126 EUR

BCA disodium salt

2810-5G each 261.6 EUR

BCA Protein Quantification Kit

E112-01 250 rxn 158.4 EUR

BCA Protein Quantification Kit

E112-02 500 rxn 182.4 EUR

BCA Protein Quantitation Kit

55R-1544 1000 assays 457.2 EUR

BCA Protein Assay Kit

  • 266.40 EUR
  • 322.80 EUR
  • 200 tests
  • 500 tests

BCA Protein Assay Kit

abx098126-100ml 100 ml 303.6 EUR

BCA Protein Assay Kit

  • 284.40 EUR
  • 811.20 EUR
  • 435.60 EUR
  • 100 tests
  • 2500 tests
  • 500 tests

BCA Protein Assay Kit

AR0146 1kit 121.2 EUR

BCA Protein Assay Kit

AR0146-1L 1kit 547.2 EUR

BCA Protein Assay Kit

AR0146-500 1kit 339.6 EUR

BCA-1/CXCL13, Human

HY-P7131 50ug 639.6 EUR

BCA Protein Quantitation Kit

K2185-1000 1000 assays 385.2 EUR

Measuring the concentration of protein nanoparticles synthesized by desolvation method: comparison of Bradford assay, BCA assay, hydrolysis/UV spectroscopy and gravimetric analysis

The desolvation technique is one of the most popular methods for preparing protein nanoparticles for medicine, biotechnology, and food applications. We fabricated 11 batches of BSA nanoparticles and 2 batches of gelatin nanoparticles by desolvation method. BSA nanoparticles from 2 batches were cross-linked by heating at +70 °C for 2 h; other nanoparticles were stabilized by glutaraldehyde. We compared several analytical approaches to measuring their concentration: gravimetric analysis, bicinchoninic acid assay, Bradford assay, and alkaline hydrolysis combined with UV spectroscopy.
We revealed that the cross-linking degree and method of cross-linking affect both Bradford and BCA assay. Direct measurement of protein concentration in the suspension of purified nanoparticles by dye-binding assays can lead to significant (up to 50-60%) underestimation of nanoparticle concentration. Quantification of non-desolvated protein (indirect method) is affected by the presence of small nanoparticles in supernatants and can be inaccurate when the yield of desolvation is low. The reaction of cross-linker with protein changes UV absorbance of the latter. Therefore pure protein solution is an inappropriate calibrator when applying UV spectroscopy for the determination of nanoparticle concentration. Our recommendation is to determine the concentration of protein nanoparticles by at least two different methods, including gravimetric analysis.

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