Micronucleus Reagent Kit

The Micronucleus BioApplication and HCS Reagent Kit provide several advantages over manual methods for genotoxicity evaluation:

  • Screen hundreds of compounds a week vs. one compound every few weeks.
  • Enable genotoxicity testing to occur earlier in the drug discovery process, saving time and money by eliminating poor drug candidates.
  • Detect early and late cytotoxicity for a high-content assay for compound toxicity.
  • Provide an answer in days vs. weeks, reducing down-time and increasing efficiency.

Micronucleus Reagent Kit Features

  • BioApplication reports the number of nuclei, micronuclei, and percentage of cells that contain micronuclei
  • HCS Reagent Kit provides optimized reagents and cell preparation protocol designed to work with the BioApplication
  • Automatically distinguishes agents that can lead to micronuclei formation by use of reference wells
  • Allows gating of subpopulations of interest using permeability as well as up to three additional channels
  • Can simultaneously measure early and late indicators of cytotoxicity by measuring the ratio of multinucleated to mononucleated cells and membrane permeability, respectively
  • Flexibility allows optimization of the assay for different cell types including, but not limited to, CHO-K1, BALB-3T3, and V79

The micronucleus assay is an important component of genetic toxicology screening programs. Micronuclei arise from acentric chromosomes and lagging whole chromosomes. Chromosome mutations of both structure and number are implicated in many human diseases. There is substantial evidence that chromosome mutations and related events in oncogenes and tumor suppressor genes of somatic cells are involved in induction and/or progression of some cancers in humans and experimental animals. Thus, the purpose of the in vitro micronucleus assay is to detect those agents that modify chromosome structure and segregation in such a way as to lead to induction of micronuclei in interphase cells. Traditional quantitative assessment of micronucleus induction in 1,000 or more cells per slide is a labor-intensive, manual task. The in vitro micronucleus assay uses cultures of established cell lines, cell strains or primary cell cultures. The cells used are selected based on their ability to grow in culture and their spontaneous micronuclei frequency. Analysis of micronuclei induction in human lymphocyte cultures indicates that the most convenient stage to score micronuclei is during the binucleate, interphase stage. Such cells have completed one cell division after chemical treatment and are therefore capable of expressing micronuclei. Treating cultures with an inhibitor of actin polymerization (cytochalasin B) results in the trapping of cells at the binucleate (or multinucleate) stage where they can be easily identified. Measuring the relative frequencies of binucleate to mononucleate cells within a culture also provides a simple method of measuring treatment toxicity. Spontaneous micronuclei formation may occur – baseline frequency of spontaneous micronuclei is approximately 1%; micronucleus frequency of cells treated with a genotoxic agent is approximately 3-fold higher or better.

The Micronucleus HCS Reagent Kit and protocol have been optimized for quantification of micronuclei in multinucleate cells. The kit provides reagents for fluorescence detection of micronuclei and nuclei, their cellular domains, and any membrane permeability changes upon treatment of cells grown on collagen-I coated microplates. The kit reagents, in combination with the Thermo Scientific ArrayScan® Readers and the Micronucleus BioApplication software, enable automated plate handling, focusing, image acquisition, analysis and quantification of micronuclei.

figure1

Figure 1. The Micronucleus BioApplication is a flexible HCS application
that automatically identifies and quantifies micronuclei in a 96-well format. Images of CHO-KI cells stained with the Micronucleus Kit HCS Reagent Kit following 28 hour incubation with cytochalasin B. Note the large number of binucleated cells within the population. Cells were exposed to a mitomycin C for 20 hours prior to cytokinesis blocking. Images were collected using the ArrayScan HCS Reader and a 20x objective. In the nuclear channel, nuclei and micronuclei are identified (see inset). The cellular channel determines the boundary of the cell for purposes of calculating the number of nuclei per cell. The permeability channel detects and excludes cells which have compromised cell membranes.

figure2

Figure 2. Effect of mitomycin C and bleomycin on micronucleus formation in CHO-KI cells
exposed to either agent for 20 hours. Cells were incubated with cytochalasin B to block cytokinesis for an additional 28 hours and stained using the Micronucleus Kit HCS Reagent Kit product. Micronucleus frequency (i.e., percentage of cells containing micronuclei) was determined in binucleated cells using the Micronucleus BioApplication and the ArrayScan HCS Reader. Data represent mean ± standard deviation calculated from eight wells at each concentration.

To order the Micronucleus Bioapplication, please contact us using the information on the top right panel.

Cat.# 製品名 容 量
S50-0018-1 Micronucleus Bioapplication n/a
K11-0001-1 Micronucleus HCS 5 x 96