This method can help researchers acquire adequate hair samples in a culturally sensitive manner. The main advantages of this technique are its culturally informed approach and the twist and roll maneuver that is used to secure the samples. Implementation of this technique will help increase the participation of African American subjects in studies about the influence of longterm cortisol exposure and health outcomes.
Our protocol takes into account a careful consideration of physical, psychosocial, and cultural characteristics relevant to the collection of hair samples from the African American adults. Visual demonstration of this method is critical for appreciation of the importance of hair in the African American community and to provide the necessary steps for improving the participants experience. Before collecting the sample, explain to the participant that the sample collected is less hair than is lost in normal everyday brushing from the back of the head.
Inform the participant how the site for the sampling is hidden by the surrounding hair and therefore not visible after collection, and that the sample will be used to measure a hormone called cortisol that is present in the hair. Show the participant a sample photo to illustrate the amount of hair that will be collected. Then, ask the participant the hair care practice questions listed in the table.
Next, escort the participant to a private area. Don a pair of non-latex gloves, and clean a pair of salon grade scissors and a large and small tooth parting comb with an alcohol prep pad. Gently pull the hair in the sample taut to allow measurement from the scalp to the ends of the strands.
Use the comb to part the hair horizontally along the posterior vertex of the scalp between the tips of the ears, and use a clip to secure the hair from the top of the part. Then, place another clip at the bottom of the part to expose a five by 10 centimeter rectangle between the two clips of loose hair, and ask the participant if they prefer a wide tooth or a narrow tooth comb. After combing the hair rectangle, ask the participant how they would like to have the remaining hair in the comb discarded.
And, grasp approximately 30 to 50 strands of hair to the right of the five by 10 centimeter rectangle. Gently pull and twist the hair away from the scalp in a rolling motion between the fingers, and use the scissors to make a clean, straight cut with the root ends aligned carefully along the cut. Use painter's tape to secure the hair sample in the center of an eight by 10 inch piece of aluminum foil, and use a marker to label the scalp end of the sample.
Fold the foil into a square so the hair cannot fall out of the foil, but without bending the hair. Place the foil into a business envelope. After sealing, use a premade barcode label to label the envelope with the participant's unique study identification number, and store the sample in a dry area at room temperature.
If you do not have a premade barcode label, you can write the participant's unique id number, date, and hair sample on an envelope. The hair cortisol can then be analyzed according to standard protocols. 21 African Americans consented to participate in this representative study.
Four participants ultimately refused to provide a hair sample, and two could not provide a sample because their hair was too short. A total of 15 usable hair samples with lengths ranging from one to 4.8 centimeters were obtained and processed from the other study participants. Technical problems included samples that were poorly aligned at the scalp end, too small of a sample, curly, or with painter's tape being over the scalp end.
Once mastered, this technique can be completed in 15 minutes if performed properly. While attempting this procedure, it's important to remember to thank the participants and offer to give the participants any unused hair. Although thinning shears have been used in previous studies, shears are not the preferred tool for cutting hair because their use results in uneven scalp end alignment and an increased time for preparing the hair samples for analysis.
This technique paved the way for researchers in the hair cortisol analysis field in obtaining culturally informed hair samples from African American study participants and in quantifying the potential influences of longterm cortisol exposure on health in African Americans. After watching this video, you should have a good understanding of how to approach and to collect adequate hair samples for cortisol concentration analysis from African American adults. Don't forget that working with salon grade scissors can be extremely sharp, so take care not to handle the blade ends of the scissors and not to press the scissors directly against the participant's scalp.
