Anti-LacI [9A5] Universal Antibody

This mouse IgG1 antibody was generated against E.coli LacI and recognizes LacI and recombinant proteins containing the LacI tag.


  • Universal antibody detects LacI from all species tested
  • Recognizes LacI as well as proteins containing LacI tags
  • Tested for Western Blot, Immunofluorescence, and Immunohistochemistry applications

The lac repressor is a DNA-binding protein which inhibits the expression of genes coding for proteins involved in the metabolism of lactose in bacteria. These genes are repressed when lactose is not available to the cell, ensuring that the bacterium only invests energy in the production of machinery necessary for uptake and utilization of lactose when lactose is present. When lactose becomes available, it is converted into allolactose, which inhibits the lac repressor's DNA binding ability. Loss of DNA binding by the lac repressor is required for transcriptional activation of the operon.

From a laboratory at the University of Virginia.

The Investigator's Annexe Part of The Investigator's Annexe program.

Catalog Number Product Size AVAILABILITY Price Qty
Anti-LacI [9A5] Universal Antibody
100ug 3-5 weeks
Regular Price:$323.00

Product Type: Antibody
Accession ID: P03023
Antigen: E. coli LacI
Host: Mouse
Molecular Weight: 38 kDa
Isotype: IgG1
Clonality: Monoclonal
Clone Name: 9A5
Specificity: Universal
Purification Method: Protein G
Tested Applications: WB, IF, IHC
Storage: -20C
Shipped: Cold packs


The lac repressor protein is wide spread in the LacIR transgenic mouse

(A) Western blot of total protein from B, brain;H, heart; Lu, lung; Li, liver; S, spleen; K,kidney; T, testis; and M, muscle of a LacIR transgenic mouse, ntT-testis of a nontransgenicmouse, reacted with a monoclonal antibody raised against the lac repressor. (B–F) Immunohistochemistry with a monoclonal antibody raised against the lac repressor on sections from (B) LacIR muscle; (C) LacIRskin; (D) LacIR hippocampus; (E) LacIR cerebellum;and (F) nontransgenic cerebellum. Scale bar indicates 500 μm in panels B, E,and F; 200 μm in panels C and D.

Adapted from: Cronin CA, et al. Genes Dev. 15: 1506-1517 (2001).

From a laboratory at the University of Virginia.
  1. Cronin CA, Gluba W, Scrable H. The lac operator-repressor system is functional in the mouse. Genes Dev. 15: 1506-1517 (2001).
  2. If you publish research with this product, please let us know so we can cite your paper.