Why a growth factor can be assayed by what it does, and what that line means

Published 24 October 2026 · REVIVE LAB UAE Research Desk · 5 min read
A responsive cell line proliferates in proportion to the IGF-1 receptor agonist added, and the concentration giving half the maximal response, the EC50, is a measure of potency. Manufacturers of IGF-1 LR3 for cell culture report this figure as a release test alongside the chemical assays. It measures function: a batch with correct mass and high chromatographic purity but a misfolded fraction gives a higher EC50. The bioassay therefore catches what the chemistry can miss, and the chemistry explains what the bioassay cannot.

How the assay works

Cells dependent on the IGF-1 receptor for growth — several lines are standard for this — are plated in defined medium with a range of concentrations of the test material and a reference. Proliferation is read after a fixed period by a dye or a metabolic indicator. The curve gives the EC50 and the test is reported relative to the reference.

Variability is higher than for a chromatographic method, so results are given with a range.

What it adds

Confirmation that the protein is folded and active, which mass and purity imply but do not prove. The swap isomer, with identical mass, has lower activity and raises the EC50. Oxidation at methionine 59 does the same. A bioassay integrates these into one functional number.

It is also the figure the biomanufacturing user cares about, since media performance depends on it.

On a research certificate

Present where the supplier runs it; absent otherwise. For the catalogue product the batch documentation states which tests were performed. This page describes what the line means where it appears.

IGF-1 LR3 is supplied by REVIVE LAB UAE for laboratory research use only, with identity and purity documented for the batch. It is not for human or veterinary use, and no dosing, administration or protocol guidance is provided.

What it costs

FormatStrengthPriceAvailability
IGF-1 LR3 Pack1 mgAED 650In stock

Delivery is AED 40 flat and free on orders over AED 700. Payment is cash on delivery anywhere in the UAE, or USDT (TRC20) in advance, which takes 5% off the order total.

Frequently asked

How the assay works?

Cells dependent on the IGF-1 receptor for growth — several lines are standard for this — are plated in defined medium with a range of concentrations of the test material and a reference. Proliferation is read after a fixed period by a dye or a metabolic indicator. The curve gives the EC50 and the test is reported relative to the reference.

Does REVIVE LAB UAE provide dosing guidance?

No. REVIVE LAB UAE supplies research materials and provides no dosing, administration or protocol guidance of any kind. Every product is sold for laboratory research use only and is not for human or veterinary consumption.

How fast is delivery in the UAE?

Stock is held in Dubai. An order confirmed before 4 PM Dubai time is dispatched the same working day, reaching Dubai and Abu Dhabi the same day and the remaining emirates within 24 hours. Delivery is AED 40 flat and free over AED 700.

IGF-1 LR3 Pack — in stock, dispatched from Dubai
HPLC-verified, lot certificate on every carton, 24-hour delivery nationwide. Browse the catalogue → All peptides UAE

Related reading

Supplied for laboratory research use only. Not for human or veterinary consumption. REVIVE LAB UAE provides no dosing, administration or protocol guidance.