Frequently asked questions: Medical gloves, protein testing, and latex allergy.

What does the modified Lowry protein test detect ?
Why does SMTL recommend testing 4 gloves from each batch?

What does the modified Lowry protein test detect ?

The modified Lowry protein assay detects levels of water soluble proteins in the gloves under test.

An assumption is made with this test that the level of protein detected correlates with the likelihood of the glove producing an immediate (Type I) hypersensitivity reaction in a user or patient.

This test method is currently being discussed as the soluble protein assay for European standard EN-455 Part 3.

There are certain problems with the test:

It is non-specific - it detects all proteins, not just allergens.
It is susceptible to interfering substances, such as surfactants and accelerators present in the latex.

SMTL are NAMAS accredited for this test.

(This question last updated on the 9-4-97, by pete@smtl.co.uk)

Why does SMTL recommend testing 4 gloves from each batch?

In the manufacture of surgical and examination glove lots, it is normal to process the left-hand and right-hand gloves separately and then pair these up at a final air-test and visual examination stage that immediately precedes placing the gloves in the final pack.

Thus, the actual hour of manufacture may differ by 12 hours or more between left and right-hand gloves in a lot. In addition, manufacturing conditions can vary throughout a batch, and thus the results from a single sample will not necessarily reflect the level of protein throughout a batch.

SMTL (in association with an independent rubber consultant) therefore suggest that, for initial assessment of gloves from any company for measurement of protein, two left and two-right hand gloves should be taken from a single nominal lot (4 samples for Examination gloves). If the overall results fall within a "reasonable" distribution from the mean value, it may then be possible to assess on a single left and single right glove for future lots (2 samples in the case of Examination gloves).

Whilst these sample sizes are not statistically significant, SMTL believe it is a pragmatic compromise between the cost of testing and useful test data.

SMTL will, of course, carry out single sample testing if required, with a consequent reduction in testing costs.

(This question last updated on the 9-4-97, by pete@smtl.co.uk)

This file is one of a number at SMTL's WWW site, dealing with frequently asked questions (FAQ's) on medical disposables and dressings. If there are any questions you would like to see answered in this FAQ file, please contact Pete Phillips at SMTL.

This site was originally set up with the aid of sponsorship from the Value for Money Unit, Welsh Office and an educational grant from Sophos Convatec.

URL: http://www.smtl.co.uk/MDRC/Gloves/Protein-FAQ.html
Last Modified: Wednesday, 26-May-1999 15:08:26 BST

Frequently asked questions: Medical gloves, protein testing, and latex allergy.

Contents

What does the modified Lowry protein test detect ?

Why does SMTL recommend testing 4 gloves from each batch?