Protocols - Page 2 of 2 - Biology Notes Online

Dot Blot Technique – Principle, Procedure and Applications

Sourav Pan (M.Sc. in Microbiology) • Updated October 19, 2026 • 20 min read

Two dot blot detection pathways showing antibodies binding immobilized proteins and complementary probes hybridizing with DNA or RNA on separate membranes.

Dot blot technique detects specific proteins, DNA, or RNA on a membrane. Explore its principle, protocol, membranes, applications, and result interpretation.

Restriction Digest – Principle, Protocol, Results and Troubleshooting

Sourav Pan (M.Sc. in Microbiology) • Updated October 18, 2026 • 26 min read

Laboratory workflow showing DNA, restriction enzyme and buffer preparation, incubation, optional cleanup and analysis by agarose gel electrophoresis.

The restriction enzymes cleave the DNA molecule at a specific site or specific nucleotide sequence, is known as recognition sequences or Restriction sites.

Reverse Blood Grouping – Principle, Requirements, Procedure, Results and Limitations

Sourav Pan (M.Sc. in Microbiology) • Updated October 18, 2026 • 15 min read

Scientific diagram showing anti-A antibodies binding to A₁ red blood cells and anti-B antibodies binding to B red blood cells, producing agglutination.

Reverse blood grouping helps confirm ABO blood types. Learn its principle, tube, slide and gel methods, results chart, limitations and typing discrepancies.

Catalase Test – Principle, Procedure, Results and Uses

Sourav Pan (M.Sc. in Microbiology) • Updated October 18, 2026 • 14 min read

Catalase Test Principle, Procedure, Result and Application.

Catalase test in microbiology: explore its principle, hydrogen peroxide reaction, slide and tube procedures, positive and negative results, and identification uses.

Xanthoproteic Test – Principle, Procedure, Results and Uses

Sourav Pan (M.Sc. in Microbiology) • Updated October 17, 2026 • 14 min read

Expected xanthoproteic test results for tyrosine, tryptophan, phenylalanine, glycine, alanine, egg albumin, milk, and gelatin, comparing orange positive and weak or negative reactions.

The xanthoproteic test detects reactive aromatic amino acid groups using nitric acid. Learn its principle, procedure, yellow-to-orange result, and limitations.