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Donkey anti-Sheep IgG

Item# BC-DAS

Many primary antibodies are now routinely prepared in sheep through the efficient immune response and the large volumes obtainable for purification. BioSite Donkey anti-Sheep IgG gold conjugates use affinity purified immuno-globulins monospecific to the sheep IgG and are sensitive to the heavy and light chain for maximum sensitivity.

FeaturesSpecifications

For high resolution electron microscope studies, BioSite gold conjugates offer the best quality in size distribution, freedom from clustering and sensitivity. In addition, because of the exceptionally high concentration of the conjugates as supplied, very small amounts of material (e.g. 1?) are required for each incubation, making the technique a very inexpensive and efficient one. Immunogold conjugates are made from the highest quality components. All BioSite conjugated immunoglobulins are affinity purified and monospecific, giving very low cross reactivity.

Narrowest Particle Size Variation

The data sheet supplied with each product certifies the mean particle diameter and coefficient of variation. With a distribution of better than 12% for 5nm and better than 8% for 10, 15, and 20nm particles, each size is effectively exactly constant, which allows multiple labeling with total absence of overlapping sizes.

BioSite gold conjugates are selected for quality control approval only if at least 85% of particles occur as singlets and less than 5% occur as triplets. Fractions having any cluster greater than triplets are discarded. For Protein A and Protein G conjugates, the specification is even higher. At least 95% of particles must exist as singlets, and no clustering of triplets or larger are allowed.

Highest Sensitivity

Sensitivity of our conjugates is tested by immunoblotting procedures using carefully measured dot blots of protein on nitrocellulose. All immunoglobulin gold conjugates must detect at least 10 picograms of protein during quality control procedures. Sensitivity is usually in the femptogram region. For Protein A and Protein G the sensitivity must be better than 100 picograms and is usually better than 10 picograms.

High Concentration

Concentration of BioSite gold conjugates is measured by the optical density at 520nm. For 5 and 10nm the O.D. is 3.0. For 15 and 20nm the O.D. is 4.0. The conjugates are generally diluted 1/100 during use.

Long Term Stability

BioSite gold conjugates are stable for at least 12 months at 4?C and much longer when frozen. Stability is measured in terms of immunoblotting sensitivity, EM labeling efficiency, background labeling and clustering. All manufactured batches are tested regularly to determine stability of performance with time and storage conditions. BioSite gold conjugates travel well at ambient temperatures and have no special shipping or packing requirements.