Tape Strips in Dermatology Research

A. J. Hughes; S. S. Tawfik; K. P. Baruah; E. A. O'Toole; R. F. L. O'Shaughnessy

Disclosures

The British Journal of Dermatology. 2021;185(1):26-35. 

In This Article

How Many Tape Strips Should be Used for Each Patient?

The number of TS used varies widely between studies (Table 2). The mass of SC removed declines exponentially with each TS[49] and SC thickness varies between individuals (16·7–30·0 cell layers on the forearm).[16] For studies quantifying proteins it is not necessary to strip the SC completely.[7] Breternitz et al. found that less pressure (using a 2N stamp) and shorter pressure application (2 s), led to a more linear increase in protein mass.[7] Less protein is collected per TS, but this is more likely to give comparable protein yield between patients.[7] Many authors recommend 15 TS per patient,[7,50] but this number depends on the component of the epidermis measured and the disease pathology.[50] For example, proteins abundant in the SC can be detected from as few as one TS.[34] Hyperkeratotic dermatoses tend to need fewer TS for protein analysis, for example, Desmoglein-1 can be detected from only one TS in lesional psoriasis.[51]

Studies that assess gene expression need more TS in order to access the granular layer, where intact cells and mRNA reside.[3] Although the number of TS needed to strip the SC varies between individuals,[19] Kim et al. demonstrated, through immunostaining of punch biopsies taken after sequential tape stripping, that 20 TS reaches the granular layer.[3] Most studies assessing gene expression sample 20 consecutive TS and use TS numbers 11–20 for RNA extraction,[3,43,47,51,52] although our own experience has found a higher yield of RNA when using all 20 TS (Figure 2).

Figure 2.

Bar chart showing RNA yields from different quantities of tape strips. Tape strips from a single set were cut into quarters and quarters were pooled according to depth. RNA was extracted using the RNeasy Plus Micro Kit (Qiagen, Hilden, Germany) using a scraper. RNA was quantified using a one-step reverse-transcriptase polymerase chain reaction kit using 18S rRNA primers against a HeLa RNA standard (RNA Quantification Kit for SYBR Green I and ROX Passive Reference Dye, ThermoFisher Scientific). P < 0·05 using the Kruskal–Wallis nonparametric analysis. Three experimental replicates were performed. Ct, cycle threshold.

The number of TS used for lipid analysis varies too. Chiba et al. detected a difference in trihydroxy-linoleic acid levels from only one TS.[53] Leung et al. compared TS levels 5 and 6 with those from levels 15 and 16.[43] This study found no difference in ceramide abundance at TS levels 5–6 between patient groups, but a substantial difference at levels 15–16.[43] The authors hypothesized that environmental oxidation of lipids affects the results of TS levels 5–6 but not levels 15–16.[43]

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