Stability & formulation screening
The problem
Misbehaving proteins can unfold, aggregate and ruin everything, but the right protein construct will hold it together and save the day. Once you’ve got the right protein, picking formulations is the next big hurdle. Screening for the best proteins and formulations requires having all the right data to advance the best candidates.
Outdated ways of looking at protein stability take way too much sample and time, and often deliver only part of the story. To keep an eye on all the ways that protein stability can go wrong, unfolding and aggregation have to be measured at the same time on the same sample. Plus, the earlier you can weed out bad candidates, the better – so it’s critical to use tiny amounts of protein.
The right tool for the job
Aunty is the ultimate stability platform with tailor-made applications to quickly study protein stability on up to 96 samples at a time – using just 8 µL per sample. Fluorescence, static light scattering (SLS) and dynamic light scattering (DLS) modes all read the same sample at the same time to give powerful insights into protein thermal stability, colloidal stability, long-term stability and viral vector stability.
While fluorescence sees unfolding, SLS will spot aggregation the instant protein molecular weight changes. DLS keeps an eye on the hydrodynamic size of aggregates big and small. Screen more candidates, formulations, or conditions to quickly figure out which is the most stable.
The proof
How Aunty spots stability problems
In a DSF experiment on Aunty, the samples heat up in the wells of the plate. Fluorescence picks up when protein unfolding occurs and calls out any melting temperatures (Tm). SLS shows when aggregation begins as an aggregation temperature (Tagg) – and that can sync up with Tm1, Tm2, or happen independently from any Tm. Because SLS intensity is related to molecular weight, it's incredibly sensitive to aggregation and is the best way to see exactly when aggregation begins. Monitor DLS during the thermal gradient and learn how big these aggregates are as they form and to what extent they eventually grow.
Accelerate stability testing
Thermal ramps characterize and rank your samples in about two hours, but a full, detailed look at stability also needs longer incubations at constant, elevated temperatures. Aunty opens the door to getting isothermal data earlier in candidate selection with a suite of apps tailor-made to monitor protein behavior over hours or days right inside Aunty. You can also rack up long term data while keeping your Aunty free for other experiments with its out-of-the-box isothermal applications – load your samples into Aunty plates, stow those in an incubator, and then pop them back into Aunty to read data once a day or once a week – it’s your call.
Aunty’s isothermal applications let you focus in on protein fluorescence or the signal from a reporter dye like SYPRO Orange – so it’s no problem to study non-fluorescent proteins or formulations that quench fluorescence. SLS and DLS chart aggregation throughout isothermal testing, keeping you on top of all stability parameters all the time. With its one-of-a-kind isothermal apps, Aunty is your stability platform for an early, low volume look at accelerated, isothermal storage testing.
Mix it up
Aunty is all about formulation screening and allows you to compare proteins, formulations, and everything else that impacts stability. A simple amino acid mutation or change of buffer can increase or decrease melting temperatures or can change unfolding behavior so that a protein with two melting temperatures now has three. Similar kinds of changes can happen with sugars, salts, surfactants, pH shifts or other protein hazards like freeze/thaw cycles.
Stack the deck
Beyond the classic DSF or isothermal experiments as protein stability assays, the flexibility of three detection technologies teamed up with temperature control makes Aunty a jam-packed toolbox of protein stability. Unfolding and aggregation data is just the gateway to isothermal stability, protein self-interaction, refolding, viscosity, and more. Aunty has applications specifically designed to rapidly extract the most possible data from the smallest sample volume of protein.
Aunty
Aunty is the fastest and highest throughput protein stability characterization tool on the planet. Period. With unrivaled fluorescence, Static Light Scattering (SLS) and Dynamic Light Scattering (DLS) skills, Aunty blasts through thermal melting and aggregation experiments — reading an entire 96-well plate of samples every minute of a thermal ramp. Sift through piles of candidates, conditions, or formulations, with as many replicates as you want. Aunty cranks out plates of results with unprecedented data resolution, so you can find your winners at breakneck speed.
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Want to learn more about how Aunty makes it easy to screen for the most stable protein or best buffer?