OUR SERVICES & PRICES
We'll be happy to serve your hair cortisol concentration analysis needs. Besides HCC, we measure salivary and nail cortisol; testosterone, corticosterone, cortisone, DHEA, and progesterone in a variety of matrixes and species; we also assess human salivary alpha-amylase activity; in addition, we have direct experience measuring blood glucose, triglycerides, cholesterol, LDL/HDL, TNF-alpha, sICAM, IL-6, and CRP in hundreds of samples. We have the equipment and trained helpers working on numerous similar projects and are ready to engage in additional projects. Our equipment can handle batches of 40 samples at a time; our current annual capacity is about 12,000 samples; we can increase it if needed.
Please note that we are a bioanalytical lab, so the top-notch quality of work (low RSDs, very low LOB and LOD), validations, advanced protocol development, publications, and grants are a priority for us. For example, we use the reverse Rainin Liquidator™ 96 pipetting technique for our ELISAs to achieve the deliverables described below; and most of our equipment is duplicated to avoid any delays.
The hair/nail cortisol measurements cost is $33.05/assay in 2024. Accounting for the annual 5% inflation, the budget for the project will be X=$33.05*the number of subjects*number of longitudinal measurements*number of segments (if applicable)*1.05N (where N= year of planned analytical measurements-2024.) Please inquire about the cost of other measurements.
Deliverables: We wash samples twice, not a single time, to remove all external contamination. We dry each hair sample completely to determine its actual weight, mill, extract three times consecutively with methanol, then acetone, then methanol over two nights, and measure each sample in duplicate using a commercial ELISA. Fifteen different questions are answered during our validation: the main point is that different amounts of milled, mixed samples analyzed provide a linear relationship with the total cortisol detected; in the range of 2.5 to 20 mg of hair, we demonstrate the R^2 of 0.994, indicating that our extraction and detection procedures are proper; thus, we need very little hair (ideally, ~20 mg; but we work with as little as 2.5 mg). The range of cortisol values in samples analyzed, in pg/mg of hair, is 1 to 300; the median is about 7 pg/mg; the detection method used, subjects’ age, BMI, sex, ethnicity, current and past stress (personal and societal) and many other parameters affect HCC; thus, the absolute values or averages of HCC need to be interpreted with great care. Cross-sectional and hair segmentation studies are fine, but we recommend longitudinal studies along with a control population whenever possible. We use the proper blank (which goes through all procedures but has no hair) and the standards on every ELISA plate. Our current lower limit of detection (LOD) is 74 pg/mL in an extract or about 1.0 pg/mg of hair; our intraplate variability is under 3%; the interplate variability is ~ 5%. Our combined extraction and detection variability is under 8%. We rely on consistent procedures and cross-comparison of longitudinal samples of subjects vs. controls processed at the same time and measured on the same plate by the same operator. We reanalyze 5% of samples randomly, dilute and reanalyze samples of high concentration, and reanalyze any samples that demonstrate more than 8% RSD within a duplicate at no additional cost to you. We also provide directions on proper sample collection techniques. For nails, we perform an extra (third) overnight extraction. Our R^2 for nail cortisol is 0.998.
See additional information in Q&A below.
sufficient amount and the scalp end IS properly marked
be it nails or hair, stainless steel balls will Convert it into a FINE powder
absorbance is under one; Measured data is in blue; Data fit in orange; LOd is low
Q&A
Should we collect 1 cm or 3 cm of hair?": It is assumed that hair grows about 1 cm/month. Thus, if you are interested in the average hair cortisol concentration (HCC) for the last month, collect one cm; if your questionnaires cover stress over three months, collecting three cm is wiser. Here is the reference we recommend regarding hair collection: Cooper GAA, Kronstrand R, Kintz P. Society of Hair Testing guidelines for drug testing in hair, Forensic Science International, Volume 218, Issues 1–3, 2012, Pages 20-24, ISSN 0379-0738, https://doi.org/10.1016/j.forsciint.2011.10.024.
"Can you please provide us with typical hair and nail collection procedures and questionnaires for participants? How about a letter of support for a grant?": Yes, it'll be our pleasure. Please call/email us (see info below), describe your project needs, and we'll send all required materials within 72 hours.
"I have a suspected Cyclical Cushing's disease. Can I send you my hair/nail sample for analysis?: 1) Due to federal medical privacy laws, our company does not accept samples from individual patients. Your family doctor or a specialist can go ahead and collect your hair according to our directions and send it to us as a de-identified, numerically labeled sample for analysis. It is to protect you and your private information. 2) A single number for hair cortisol concentration is challenging to interpret. Both old and new, chronic and acute stress events affect it; medications, race, gender, age, pregnancy, and even exercising are associated with it; thus, it's best to collect longitudinal data from a subject with medical treatment going on at the same time to see if such treatment is helping. Without proper context, a single measurement will not likely help you. 3) Find professionals working with Cushing's at national medical research institutions. I'm sure they will be willing and able to help you. We collaborate and analyze samples for them.