Bacteriology

ONPG: β-galactosidase Test

Last updated on June 11th, 2021O-Nitrophenyl-β-D-galactopyranoside (ONPG) is structurally similar to lactose (i.e. ONPG is an analog of lactose), except that orthonitrophenyl has been substituted for glucose. On hydrolysis, through the action of the enzyme […]

Viral Transport Medium (VTM)
Culture Media

Transport Media Used in Microbiology Lab

Last updated on June 21st, 2021Transport media are essentially solutions of buffers with carbohydrates, peptones and other nutrients (excluding growth factors) designed to preserve the viability of bacteria during transport without allowing their multiplication. The […]

Leucine Aminopeptidase test
Bacteriology

Leucine Aminopeptidase (LAP) Test

Last updated on June 23rd, 2021Leucine Aminopeptidase (LAP) test is used to identify catalase-negative gram-positive cocci. Specifically, it differentiates Aerococcus and Leuconostoc from Streptococcus, Enterococcus, Lactococcus, and Pediococcus. The LAP disk is a rapid test […]