Bio-protocol Preprint Repository

Q&A Published: Oct 5, 2026

α-Amylase Inhibition Assay (Starch-Iodine Method)Mohammed Abu Tayab1’ *1 Department of Pharmacy, International Islamic University Chittagong, Chattogram 4318, BangladeshCorresponding author: abutayab.me@gmail.com Abstractα-amylase inhibition assay is an in vitro test for determining the potential antidiabetic activity of plant extracts and other substances, using acarbose as a standard inhibitor. The assay, known as the starch-iodine method, measures the remaining starch after incubation with α-...

Q&A Published: Oct 5, 2026

Pyruvate kinase/lactate dehydrogenase coupled assay Overview:This is a coupled enzyme assay that indirectly measures ATP consumption by coupling the ADP produced to NADH oxidation via:Pyruvate Kinase (PK): converts ADP + PEP → Pyruvate + ATPLactate Dehydrogenase (LDH): converts Pyruvate + NADH → Lactate + NAD⁺The decrease in NADH absorbance (typically at 340 nm) or fluorescence (excitation ~340 nm, emission ~460 nm) reflects ATP consumption by the kinase of interest (e.g., Btk). Stock Solutions ...

Q&A Published: Oct 2, 2026

Estimating phycobilisome coupling to photosystems I and II and the PSII:PSI ratio in cyanobacteria using low-temperature (77 K) fluorescence spectroscopy  Tomáš Zavřel1, Anna Segečová1, Mariann Kis2, Eva Kotabová3, Ondřej Prášil3, Jan Červený1, Gábor Bernát2  1Department of Adaptive Biotechnologies, Global Change Research Institute, Czech Academy of Sciences, Brno, Czechia2HUN-REN Balaton Limnological Research Institute, Tihany, Hungary 3Centre Algatech, Institute of Microbiology of the Czech Ac...

Q&A Published: Oct 1, 2026

J2 antibody immunofluorescence Cell Plating and Knockdown:Place 12mm circular cover slips into a 24-well plateUV sterilize for 10minWash once with DMEM mediaHarvest HeLa cells and countDilute cells to 40K/ml and plate 1ml of cells per wellDuring trypsinization, mix:50ul of OptiMEM with 1ul of RNAimax per sample (Tube A)Incubate at RT for 5 min50ul of OptiMEM with 1ul of Control or SETX siRNA per respective samples (Tube B)After 5min, add Tube A to Tube B, mix and incubate at RT for 20 minSplit T...

Q&A Published: Sep 18, 2026

Optimized ex vivo preservation and FACS isolation of Drosophila ovarian germline and follicle cells for cell-type-specific gene-expression analysisRounab Sarkar¹, Sautan Show¹, Anjali Mohan¹, Upendra Nongthomba¹*1 Department of Developmental Biology and Genetics; Indian Institute of Science; Bengaluru – 560012, India.* Corresponding author: Prof. Upendra Nongthomba, upendra@iisc.ac.inAbstract:Cell-type-specific molecular profiling of the Drosophila melanogaster ovary is important for understandi...

Q&A Published: Sep 16, 2026

Cell Surface CD74 Flow Cytometry ProtocolRequired MaterialsReagents:Thawing/Stim Medium: RPMI 1640 medium supplemented with 5% FBS, 1% Glycine (2 mL of 100× stock), and 1% Pyruvate (2 mL of 100× stock)Staining Solution: 1× PBS supplemented with 5% BSAAntibodies/Dyes:FITC-conjugated anti-CD74 (Clone: MB731; BD Biosciences)APC-conjugated anti-CD11b (Clone: ICRF44; BioLegend)7-aminoactinomycin D (7-AAD; BD Biosciences)Equipment: Water bath (37°C), Centrifuge, Accuri C6 flow cytometer (BD), 96-well ...

Q&A Published: Sep 15, 2026

We recommend optimizing the procedure for dissociated mouse hepatocyte spheroids, as the dissociation process itself may affect mitochondrial ROS levels and cell viability.MitoSOX stock preparation and working concentrationMitoSOX Red (Thermo Fisher Scientific) was dissolved in DMSO to prepare a 5 mM stock solution. Immediately before use, the stock was diluted in pre-warmed DPBS to a final working concentration of 5 μM. Stock aliquots were protected from light and repeated freeze–thaw cycles we...

Q&A Published: Sep 14, 2026

  Abstract:With phosphatidylcholine and L-serine, phosphatidylserine synthase 1 (PSS1) synthesizes phosphatidylserine, a phospholipid that is a key component in cell membranes. Here, we provide a step-by-step protocol examining the enzymatic acidity of PSS1 in vitro. This in vitro assay quantitatively measures Choline, a byproduct generated in the biochemical reaction, featuring simple operation, high sensitivity and low cost without the requirement for radioactive labeling. It enables rapid eva...

Q&A Published: Sep 14, 2026

 For morphology analysis, microalgae samples were diluted in TAP media to a final density of 1×106 microalgae/mL, then 10 µL were loaded onto a glass slide and taken to the light microscope. Morphology was evaluated by optical microscopy (Dmi1 microscope, Leica), with 10x/0.4 and 40x/0.65 objectives and imaged with a standard MS60 digital camera (Mshot). Cell area quantification was done on 40x images with ImageJ, where a background threshold was applied and the total area of each separate micro...

Q&A Published: Sep 9, 2026

Calcium Switch Assay for Synchronized Junction Disassembly and Reassembly in Human Intestinal Epithelial MonolayersArturo Raya-Sandino and Asma Nusrat*Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USAFor correspondence: anusrat@umich.eduAbstractThe calcium switch assay provides a synchronized system for examining the disassembly and reassembly of calcium-dependent epithelial cell-cell junctions1-3. Here, we describe a protocol for evaluating the recruitment of th...