Casein Colloid/ELISA Buffers from RDI Divison

28th Aug 2021

POLY-HRP BUFFER SYSTEMS-in the use of the POLY-HRP-Conjugates (and other charged conjugates) , a strong colloidal blocking buffer may be of use in reducing any background interactions due to charge-charge interactions of the antigen, antibodies and conjugates. We are pleased to announce the availability of 2 formulations- available for researchers who do not want to prepare their own buffer. Each formulation has been used in highly specific and sensitive immunoassays.

cat#RDI-M2052clb CASEIN COLLOID BUFFER 5% 100ml $175.00/btl

-a specially prepared biotin free casein in a proprietary base to dilute with your assay buffer 5X to yield 500ml of working solution. Contain 5% casein.


POLY HRP DILUENT (1Liter) (new formulation June 25, 2001)

containing 1.375% casein buffer (virtually biotin free*) in a 0.15M PBS (120mM NaCl, 30mM sodium phosphate) buffer pH 7.3 with 0.05% microcide I ( preservative ,non mercury containing).

cat#RDI-PHRPDILX CASEIN Buffer II 1 Liter $250.00/Liter

Bulk Material quoted on request (10 Liter carboy $2375.00 cat#RDI-PHRPDILX-10L)

LOT# see label on bottle Expiration: see label on bottle

Before Use: Make sure cap is tightly closed . Gently Invert and swirl to mix before use. DO NOT VORTEX (will produce excess foam).

Use: Ready to Use Formulation. Use full strength . Dilute POLY-HRP-Streptavidin immediately before use as determined for your assay (generally 1:10K, ie, 5ul with 50ml buffer). Because each assay system must be optimized, it is recommended you first use the POLY-HRP-Streptavidin in your own assay buffer and then try substituting this diluent buffer running an assay in parallel. Best results may be obtained when plates are blocked for 1 hour at room temp before use (or overnight) using 300ul of this buffer or a biotin free BSA formualtion (skim milk not recommended) , wash 4-5X , and then use this buffer as your assay/diluent buffer. The strong blocking effects of casein can reduce non specific binding and lead to increased sensitivity. This casein has also been tested and found to contain biotin levels below detectable influence on the Poly-HRP-Streptavidin conjugates.

MSDS FORM INFORMATION: For In Vitro Research Use Only-Not for Use in OR ON Humans or Animals. Observe proper good lab procedures. Contact your safety officer for further information on proper handling of these and similar products. Wearing of disposable latex gloves, lab coats and suitable protective eyewear is recommended when using this and other research products. Do not pipet this or any product by mouth (use disposable pipetting devices).

Hazardous Ingredients as identified on July 6, 1999

Reagent: This product contains a proprietary formulation of materials. For safety purposes, this product contains the following items in various proportions. Researchers should be familiar with possible hazards involved with the use of any of these items and be comfortable using products with unknown hazards.

Biotin free casein cas#68408-23-6

Sodium Chloride cas#7647-14-5

Sodium Phosphate Dibasic cas#7558-79-4

Sodium Phosphate Monobasic cas#7558-80-7

Sodium hydroxide cas#1310-73-2

Hydrochloric Acid cas#7647-01-0

5 bromo-5-nitro 1,3 dioxane cas#30007-47-7


LOT# see label on bottle Expiration: see label on bottle.