rev: April 5, 2005
Return (Home Page)
Return (Immunoassay Enhancers)
for Researchers and Manufacturers
HRP CONJUGATE STABILIZERS
-NEW April 2005:
-ideal for poly-HRP conjugates and conventional HRP conjugates diluted to working strength!
RDI-SA3-RHT is a novel product having 100% synthetic formula. It is absolutely protein-free reagent containing no organic substances of the animal, plant or microbial origin. It does also not contain phenol compounds or other volatile organic substances having distinctive "chemical odor". This product contains no listed hazardous or toxic products.
Code Number: #RDI-SA3-RHT $500.00/1Liter $438.00/liter 25+ Bulk on request
-limited number of 100ml evaluation sizes available for OEM use
Storage: +2°C/+8°C; neutral/borosilicate type I glass, PC/PET/PETG/PP/HD-PE
Expiration date: 04/2006+ (longer after re-check)
Appearance: Transparent liquid, 0.45/0.2/0.1µm-filterable
Odor: Weak, characteristic
Preservative/anti-microbial: 5-Nitro-5-Bromo-1,3-Dioxan (BND), 1500 ppm
QC release (ELISA-based NSB-eliminating and detection strength boosting activity use test): Passed
NOTE: This product is for in vitro research or further IVD manufacturing use only.
SA3-RHT is a novel product having 100% synthetic formula. It is absolutely protein-free reagent containing no organic substances of the animal, plant or microbial origin. It does also not contain phenol compounds or other volatile organic substances having distinctive "chemical odor". This product contains no listed hazardous or toxic products.
SA3-RHT will provide real-time stability to ready-to-use SA-PolyHRP conjugates at +2°C/+8°C (beyond one year) and room temperature (at least one year). SA3-RHT will support SA-PolyHRP conjugates also in the very low working strength concentrations down to 200-100-50 ng/ml. It will maintain activity of diluted SA-PolyHRP conjugates in working strength ready-to-use format at a level of 90-to-100% of the initial activity during at least 4 weeks stressing at 37°C. That way SA3-RHT makes SA-PolyHRP suitable for routine clinical IVD applications through finally making it compliant with mandatory IVD requirements on stressed/accelerated reagent stability at elevated temperatures.
The major advantage of a liquid HRP-conjugate is it eliminates the chance for human error when dissolving or diluting the lyophilized or concentrated conjugate. Adding too much or not enough buffer results in assay to assay variation. Until now, the disadvantage of this format was the inherent instability of the liquid HRP-conjugates. This problem has now been addressed! The HRP-CONJUGATE STABILIZER is formulated to allow you to provide pre-diluted, READY-TO-USE CONJUGATES. This product contains Phosphate buffered Saline with BSA and other proprietary reagents, 0.01% thimerosal added*.
cat#HRP-Stab READY-TO-USE : This formulation was designed to reconstitute lyophilized or concentrated HRP-conjugates. Conjugates are titered and diluted to working concentrations with the HRP-CONJUGATE STABILIZER. Many HRP-conjugates prepared in this manner will maintain HRP activity for up to 2 years at 4 Deg C.
HRP Stabilizing Diluents (additional formulations)
We recommend our HRP-Conjugate Stabilizer cat#HRP-STAB-1X as the best overall stabilizer for HRP conjugates. This formulation has additional stabilizers and formulary products to meet more demanding needs.
However, we also offer 4 other formulations at a lower cost for applications that might not need our full featured product. As always, you must independently test these products for your own application.
CAT#RDI-HRPSTAB-1X or HRP-STAB-1X ALSO AVAILABLE PRESERVATIVE FREE
$500.00/Liter Allows you to add other presevatives as microcide I ).
$438.00/Liter for 11+ liters use cat#RDI-HRPSTAB-1XP $531.00/Liter
$312.00/Liter 50 or more $375.00/liter 50+
-this is also a 10X formulation which can be used with pre-diluted HRP conjugates but also contains proprietary inert proteins that act to further stabilize peroxidase conjugates.
FORMULATION II (non PBS system)
The major advantage of a liquid HRP-conjugate is it eliminates the chance
for human error when dissolving or diluting the lyophilized or concentrated
conjugate. Adding too much or not enough buffer results in assay to assay
variation. Until now, the disadvantage of this format was the inherent
instability of the liquid HRP-conjugates. This problem has now been addressed!
The HRP-CONJUGATE STABILIZER Formulation II is formulated to allow you to provide pre-diluted, READY-TO-USE CONJUGATES (in an non/minimal Phosphate Buffer System ).
This product is prepared in a proprietary buffer system and contains a non mercury containing preservative (no azide, no thimerosal).
cat#HRP-Stab2 READY-TO-USE : This formulation was designed to reconstitute lyophilized or concentrated HRP-conjugates. Conjugates are tittered and diluted to working concentrations with the HRP-CONJUGATE STABILIZER II.
Use at full strength or dilute 1:1 with 10mM MOPS Buffer, pH 6.8-7.2 or 0.85% NACL. The use of Phosphate buffers at more than 10% or 1.5mM Phosphate will cause precipitation).
See our cat#RDI-HRPSTAB-1X. for our regular formulation.
Store at 4 DEG C and protect diluted material from light.
Conjugates prepared in this manner will maintain HRP activity for up to 2 years at 4 DEG C. (actual time must be determined with your particular conjugate and assay characteristics).
CAT# RDI-HRPSTAB2 =$375.00/Liter
$344.00/Liter for 5-9 liters
$325.00/liter 10-20 Liters
Please allow 2 weeks for delivery on multi-liter quantities (to ensure product from same production lot!).
You should titer your conjugate with each batch.
Minimize the number of times you open and close the bulk stabilizer bottle. Try to maintain aseptic techniques. Ideally, sterile filter your conjugate prior to addition to the stabilizer (or after dilution for maximum stabilizing effect).
FOR RESEARCH OR FURTHER MANUFACTURING USE ONLY.
Technical Recommendations for HRP Stabilizing Solutions:
You should titer your conjugate with each batch. Our testing shows you may need slightly more of your conjugate but the long term stability of the "working conjugate" makes for a much more reproducible product.
Minimize the number of times you open and close the bulk stabilizer bottle. Try to maintain aseptic techniques. Ideally, sterile filter your conjugate prior to addition to the stabilizer (or after dilution for maximum stabilizing effect). DO not Sterile filter POLY-HRP products, maximum filtration at 1.0 microns. Package diluted conjugates in oxygen barrier bottles (PET or brown glass lyophilization vials with stoppers and tight caps). NOTE: Stability of HRP conjugates is prolonged by keeping conjugates cool and reducing exposure to light and oxygen. Thorough vacuum degassing with nitrogen flushing of all buffers, conjugates and diluents will extend diluted conjugate stability under severe conditions.
Our primary formulation of HRP Stabilizer is a proprietary formulation made with certified reagents under a standardized GMP production protocol. I regret that I cannot give you any additional details on its preparation or formulation, howvere it is a PBS buffer based system. For those assays that might owrk better with non PBS based buffers, see our HRP-STAB2 (Formulation II).
As for validating an extended stability with such a product, this is also too dependent on the product to give you much information. However, the following is a "SAMPLE" protocol of process that must be investigated for using such a product.
1) You should first titer your conjugate with the HRP stabilizer (full strength or 1:1 with sterile degassed bufer) to obtain a working dilution. Generally, you will need approx 10% more conjugate initially than if used with a standard buffer diluent.
2) Then , you should sterile filter the conjugate (if possible, or 0.45 micron filtration with our POLY-HRP products) and add it to the stabilizer. If you have the capabilities and you have a very unstable conjugate, you may also wish to add the components, mix in a teflon, glass or plastic (not metal) lined container under a nitrogen atmosphere. Degas with 3 or 4 flushes of nitrogen. DO NOT agitate or mix vigorously in a regular air atmosphere. Keep mix at 4 DEG C or lower during process.
-if you conjugate is susceptible to bacterial decay, you can add additional thimerosal or other non azide preservatives as desired (as our microcide I).
3) Bottle the cold, diluted material with nitrogen pressure or gravity fill into pre-chilled low oxygen transfer bottles. Ideally, brown borosilicate glass with stopper and screw cap or tight crimp seals. Also good is PETE type cell culture bottles (which have low O2 and CO2 transfer).
4) Stability testing: The only truly applicable method is real time studies in various packages at your intended storage conditions 4-8 DEG C. One generally would perform 24 hours at 37 DEG C and then 24 hours at 20 DEG C and then regular store at 4-8 DEG C (this simulates generally shipping conditions of one stressful day in a delivery truck, one day waiting for receiving to put kit in refrigerator and then the remaining time for storage as needed).
5) Some initial accelerated stability testing can be performed to stress the conjugate and see if any changes in packaging methods will have an effect. These include the following: a) make up 16 bottles each of your conjugate ( 8 in the stabilizer, and 8 in your regular assay buffer or HRP diluent).
Before bottling, remove enough to run your assay (to set baseline characteristics).
Additional bottles may be made if your decide to test different packages (ie, glass versus plastic etc). Each bottle MUST be made up to the volume intended for final use so that head space/void space is at actual dimensions.
b) Place Two sets in 37 DEG C bath, two at room temp, two at 4-8 DEG C and two at -20 DEG C (to study frozen effects long term).
c) Each 24 hours, open one designated set, remove only enough to run a standard curve . Close vial and place back in designated temp. Repeat every 48 hours until such time that the 37 DEG C conjugate looses enough activity to make it unsuitable for your assay. Then continue testing once per week observing the room temp studies. At conclusion of study, check the unopened vials and compare that activity with activity at beginning and from the last of your sampled vials (this checks to see if some of the additional loss of activity was due to opening and closing the vials themselves).
As you can see, this requires a comprehensive evaluation. Since there are too many factors involved, we cannot say what effect any one item might have on the result. The varied stability/purity of the HRP conjugate itself will have a great effect on the stability of any stabilizer to be of help. NOTE:The conjugate stabilizer is formulated to protect the HRP moiety (not the antibody or any protein bonds).
From various customer response, the combination of our HRP-STAB-1X and our TMS-S has made for a very stable and well received assay.
RDI Division of Fitzgerald Industries Intl
(Research Diagnostics Inc)
34 Junction Square Drive
Concord MA 01742-3049
phone (978) 371-6446 or (800) 370-2222
fax (978) 371-2266
Email : email@example.com
Return (Immunoassay Enhancers)