Microsomes

Your metabolic tools for drug discovery & development GIBCO® microsomes & other liver subcellular fractions

  • Large pooled lots for reproducible, long-term studies
  • Fractions carefully isolated by experts in hepatic biology
  • Microsomes functionally tested for select CYP450 and Phase II enzyme activities

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Human microsome pools and subcellular fractions

Subcellular fractions, derived from the endoplasmic reticulum of liver, contain a rich variety of metabolic enzymes for assessing the in vitro metabolism of drug candidates (Table 1) and are suitable for a variety of experiments:

  • Cytochrome P450 inhibition studies
  • Metabolic stability
  • Cytochrome P450 phenotyping
  • Metabolite characterization

50 donor human liver microsome pool
Designed to maximize functionality for all your study types- suitable for inhibition, clearance, or metabolic identification.

  • Equal representation of all 50 donors
  • Activities representing the typical patient population

11 specialty human liver microsome pools
Prepared with 5 to 20 donors each and pooled for your convenience according to age, gender, body mass index, high 3A activity, and high 2D6 activity.

Customized microsome pools

Our scientists will create a customized pool specifically for your unique research needs using our large, fully characterized single-donor database.

We provide liver subcellular fractions from a variety of tox species, including human, nonhuman primates (Cynomolgus Monkey and Rhesus Monkey), dog (Beagle), rat (Sprague-Dawley), mouse (CD-1),  and trout (Oncorhynchus mykiss).  Custom species are available upon request. 

Each product contains an average representative pool of donors.  Human microsome pools are fully characterized (Km and Vmax) according to GLP standards for major cytochrome P450 activities and select Phase II enzymes using FDA recommended substrates (Tables 2-3).


Table 1. Relevant applications for liver subcellular fractions.

Metabolic  EnzymesLiver MicrosomesLiver S9 FractionsLiver Cytosol
Aldehyde Oxidase
 X
X
Cytochromes P450 (CYP)X
X
 
Flavin Monooxygenases (FMO)
X
X
 
Glutathione Transferase (GST) X
 
Monamine Oxidase (MAO)
 X
 
Sulfurotrnasferase (SULT)
 X
X
Uridine Glucuronide Transferase (UGT)
X
X
 

Table 2. Cytochrome P450 and Phase II enzymes tested in Gibco human microsome pools.

Enzyme MonitoredMarker SubstrateIncubation (min)Protein Concentration (mg/ml)Metabolite
CYP1A1/2
Phenacetin
30
0.1
Acetaminophen
CYP2A6
Coumarin
5
0.025
7-Hydroxycoumarin
CYP2B6
Bupropion
20
0.25
Hydroxybupropion
CYP2C8
Paclitaxel
10
0.075
6α-Hydroxypaclitaxel
CYP2C9
Tolbutamide
20
0.1
Hydroxytolubutamide
CYP2C19
(S) Mephenytoin
30
0.1
4'-Hydroxymephenytoin
CYP2D6
Dextromethorphan
15
0.2
Dextrorphan
CYP2E1
Chlorzoxazone
20
0.1
6-Hydroxychlorzoxazone
CYP3A4/5
Midazolam4
0.025
1'-Hydroxymidazolam
CYP3A4/5
Testosterone7
0.05
6β-Hydroxytestosterone
CYP4A11
Lauric Acid
15
0.2
12-Hydroxydecanoic Acid
FMO
Methyl p-Tolylsulfide15
0.05
Methyl p-Tolylsulfide
UGT
7-Hydroxycoumarin
30
0.2
7-Hydroxycoumarin Glucuronide

Table 3. Kinetic parameters for the Gibco 50 donor human liver microsome pool.

IsoformMetaboliteKm(μM)Vmax (nmol/min/mg)
CYP1A2Acetaminophen780.73
CYP2A67-Hydroxycoumarin1.10.53
CYP2B6Hydroxybupropion640.29
CYP2C86α-Hydroxypaclitaxel5.50.15
CYP2C9Hydroxytolbutamide2200.19
CYP2C194'-Hydroxymephenytoin340.031
CYP2D6Dextrophan3.20.13
CYP2E16-Hydroxychlorzoxazone701.4
CYP3A46β-Hydroxytestosterone194.0
CYP3A41'-Hydroxymidazolam1.61.1

For Research Use Only. Not for use in diagnostic procedures.