thesciencenotes

The diagram shows three sequential test tubes illustrating the qualitative analysis of proteins containing aromatic amino acids. Step 1 shows a test tube labeled "NITRATION" where concentrated nitric acid ($HNO_3$) is added to a protein sample, beginning to form a light yellow color representing nitrated aromatic amino acids. Step 2 shows the test tube being gently heated over a small burner flame, producing a distinct yellow substance labeled "Xanthoproteic Acid" to ensure reaction completion. Step 3 shows sodium hydroxide ($NaOH$) alkali being added via a dropper, resulting in a dark yellow-orange positive result due to the intensification into an orange salt.

June 3, 2026 Biochemistry Protocols and Techniques

Xanthoproteic Test: Qualitative Protein Analysis Using Nitric Acid

Learn how the xanthoproteic test uses nitric acid to detect aromatic amino acids in proteins, including principle, procedure, results, uses, and limitations. Read more

Labeled diagram of a eukaryotic cell nucleus showing the nuclear envelope, outer nuclear membrane, inner nuclear membrane, perinuclear space, nuclear pore complexes, nucleoplasm, nucleolus, chromatin, chromosomes, ribosomal subunits exiting through nuclear pores, and the endoplasmic reticulum connected to the outer nuclear membrane.

June 3, 2026 Biology

Nucleus: Definition, Structure, Functions, DNA Organization, and Diagram

The nucleus is a membrane-bound organelle that stores DNA and controls gene expression in eukaryotic cells. Learn its structure, nucleolus, chromatin, chromosomes, nuclear pores, and functions. Read more

RNA-seq workflow infographic showing steps from experimental design to sequencing, data analysis, and reporting.

June 1, 2026June 1, 2026 Cell and Molecular Biology

RNA-Seq: Principles, Workflow, Data Analysis, and Applications in Transcriptomics

RNA sequencing, commonly called RNA-seq, is a high-throughput sequencing method used to study the transcriptome. The... Read more

Infographic explaining SNP genotyping methods including SNP arrays, PCR-based assays, fragment analysis, and DNA sequencing, with applications in medicine and genetic research.

May 30, 2026May 30, 2026 Genetics

SNP Genotyping: Methods, Applications, and Benefits

Single nucleotide polymorphisms, or SNPs, are among the most common forms of genetic variation. They occur... Read more

May 28, 2026 Genetics

Genetic Screens: Types, Methods, and Applications

Learn what genetic screens are, how forward and reverse screens work, and how they help scientists study genes, disease, and drug targets. Read more

Trihybrid cross infographic explaining Mendel’s three-trait inheritance, F1 trihybrids, 8 gametes, forked line method, and 27:9:9:9:3:3:3:1 phenotypic ratio.

May 28, 2026 Genetics

Trihybrid Cross: Definition, Forked Line Method, and Phenotypic Ratio

A trihybrid cross is a genetic cross that studies the inheritance of three traits at the... Read more

Mendel’s dihybrid crosses infographic explaining pea plant inheritance, independent assortment, 9:3:3:1 phenotypic ratio, linkage, and recombination.

May 28, 2026 Genetics

Dihybrid Cross: Mendel’s Law of Independent Assortment Explained

A dihybrid cross is a genetic cross that studies the inheritance of two traits at the... Read more

Mendel’s monohybrid crosses infographic showing pea plant inheritance, dominant and recessive traits, F1 and F2 generations, and the Law of Segregation.

May 28, 2026 Genetics

Monohybrid Cross: Mendel’s Pea Plant Experiments, Dominance, and Law of Segregation

A monohybrid cross is a genetic cross between two organisms that differ in only one trait.... Read more

Punnett square infographic showing genotype, phenotype, alleles, inheritance probability, examples, and limitations.

May 28, 2026 Genetics

Punnett Square: Definition, Examples, Uses, and Limitations in Genetics

A Punnett square is one of the most useful visual tools in introductory genetics. It helps... Read more

Scientist in graduation gown reflects on the PhD journey, with laboratory and research imagery symbolizing sacrifice and endurance.

May 25, 2026May 25, 2026 News & Blogs

A PhD Is Not Nothing: An Open Letter to Those Who Dismiss the Journey

PhD is not nothing. This open letter tells the truth about the sacrifice, endurance, failure, and resilience behind earning a PhD in cell and molecular biology—and why the journey deserves respect. Read more

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