Bio-Rad Criterion™ XT Tris-Acetate Precast Gels User Manual
Page 16

Total Protein Blot Stain
Method
Sensitivity
Optimal Protein Load
Advantages
Disadvantages
SYPRO Ruby protein
2–8 ng
~0.2 µg/band
Compatible with mass
Multiple-step protocol;
blot stain
spectrometry, Edman-based
Requires imaging
sequencing, and standard
instrument for
immunological procedures
maximum sensitivity
Colloidal gold stain
1 ng
~0.1 µg/band
Sensitive, one step
Not compatible with
nylon membranes
Enhanced colloidal
10–100 pg
~0.1 µg/band
Increases sensitivity of
Multiple steps
gold detection kit
colloidal gold stain
Amido Black
100–1,000 ng
~5 µg/band
Standard membrane
Low sensitivity
stain, economical
Immunoblot Detection
Method
Sensitivity
Optimal Protein Load
Advantages
Disadvantages
4CN colorimetric (HRP)*
500 pg
~0.25 µg/band
Fast detection
Results may fade
DAB colorimetric (HRP)
500 pg
~0.25 µg/band
Fast detection
Contains toxic
chemicals
Opti-4CN colorimetric
100 pg
~0.05 µg/band
Color does not fade
More expensive than
(HRP)
4CN
Amplified Opti-4CN
™
10 pg
~0.005 µg/band
High sensitivity, low
Amplification requires
colorimetric (HRP)
background
additional steps
BCIP/NBT colorimetric
100 pg
~0.05 µg/band
Sensitive; multiple antigens
May detect endogenous
(AP)
enzyme activity
Amplified AP*
10 pg
~0.005 µg/band
High sensitivity
Amplification requires
additional steps
Immun-Star
™
10 pg
~0.005 µg/band
Long-lasting signal,
Requires visualization
chemiluminescent (AP)
short and multiple
on film or instrumentation
exposures possible
*(HRP) horseradish peroxidase; (AP) alkaline phosphatase
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