TiterMax® Gold - A New and Improved Research Adjuvant

Introduction

After years of research to identify and characterize the scientific basis for adjuvant activity, CytRx Corporation released a research adjuvant, TiterMax®. It was originally designed to meet the specific needs of investigators for an immunoadjuvant that was at least as effective as Freunds Complete Adjuvant, but safer and easier to use. In 1996, CytRx Corporation released a new and improved water-in-oil adjuvant, TiterMax® Gold, which is now available for purchase.


The key to the potency of TiterMax® Gold lies in both the immunostimulatory activity of its new block copolymer, CRL-8300, and its ability to form a stable water-in-oil emulsion. TiterMax® Gold can be used with a wide variety of antigens which can be entrapped in a water-in-oil emulsion. Like TiterMax® Classic, TiterMax® Gold does not contain mineral oil, proteins, polysaccharides or other microbial products, thereby minimizing or eliminating the undesirable side effects caused by Freunds Complete Adjuvant.

 

Comparison Data

Procedures

Studies were conducted using ovalbumin with various research adjuvants. Six to eight-week-old female C57BL/6 mice (10 per group) were immunized with a constant dose of 25 µg ovalbumin with each commercial adjuvant. Optimal dosing regimens for TiterMax® Gold were determined. Secondary immunizations were with antigen and adjuvant. All commercial adjuvants were prepared, injected, and boosted according to the manufacturers' protocols. Serum samples were obtained at various times after immunization (days 28, 56, and 84) and IgG antibody titers against ovalbumin were determined using a microtiter plate ELISA. Data is expressed as units/ml against an in-house standard.

 

Results


TiterMax® Gold injected intramuscularly, outperformed the other commercial adjuvants at all time points (days 28, 56 and 84). TiterMax® Gold was found to be effective following single and multiple immunizations. For polyclonal antibody production, we recommend immunizing mice with a 100 or 200 µl dose (TiterMax® Gold and antigen), injected intramuscularly into each hind quadricep.

 


For years researchers have been immunizing with Freunds Complete Adjuvant. Recently, many investigators have been searching for new adjuvants with less toxicities. We injected C57BL/6 mice with TiterMax® Gold, Freunds Complete Adjuvant, and Freunds Incomplete Adjuvant at Day 0. Mice initially injected with TiterMax® Gold were boosted with the same dose of TiterMax® Gold , while mice initially injected with FCA and IFA were boosted with IFA.

Results at day 28 were comparable. However, mice injected with TiterMax® Gold continued to have increasing titers at day 56 and 84, while the titers of mice injected with FCA and IFA began to level off.

Examples of Successful Dosing Regimens
for TiterMax® Gold*

SPECIESINJECTION ROUTETOTAL INJECTIONSVOLUME PER INJECTIONSITE(S)
MICE IM 1 100 ul Hind quadricep
SC 1 100 ul Base of tail or neck
RATS IM 2 100 ul Each hind quadricep
GUINEA PIGS IM 2 100 ul Each hind quadricep
SC 4 100 ul Over both shoulders and both hind quadriceps
RABBITS IM 2 100 ul Each hind quadricep
SC 4 200 ul Over both shoulders and both hind quadriceps
CHICKENS/ TURKEYS IM 2 100 ul Each breast
SC 1 200 ul Neck
CATS/DOGS IM 2 200 ul Each hind quadricep
SC 1 200 ul Along neck
RHESUS MONKEYS IM 2 200 ul Each hind quadricep
SC 4 100 ul Along inner thigh
GOATS/ SHEEP IM 4 400 ul 2 injections in each hind quadricep
COWS /HORSES SC 10 200 ul Along neck


Good immune responses have been achieved with Water to TiterMax® Gold ratios of 50:50.

*These are estimated routes and dosages that have proven successful with the original formulation of TiterMax®. Dosing regimens that have been used with other adjuvants may certainly use TiterMax® Gold.