please rephrase the next paragraph in a formal academic templet " Tissue Specimens: 
Three sections of 5-micron thickness were split from the paraffin blocks; one section was stained with hematoxylin & eosin to evaluate the diagnosis; other two sections were mounted on positive charged slides and immunostained by P15 & P16. 
Immunohistochemistry:
For immunohistochemical study; positively charged slides (Biogenix) were prepared from each paraffin block and immunostained with primary antibodies:  rabbit polyclonal antibody against P15 (INK4b) (Abcam, Cambridge, MA; diluted 1:500) and rabbit monoclonal antibody against P16 (INK4a) (Abcam, Cambridge, MA; diluted 1: 250). Immunohistochemical reactions were performed using Labeled Streptavidin-Biotin2 System- Horseradish Peroxidase (LSAB2 System-HRP), based on a modified labelling technique called Avidin-Biotin (LAB), in which a secondary biotinylated antibody forms a complex with peroxidase-conjugated streptavidin molecules. Entire antibody complex is rendered noticeable with the addition of an effective substrate chromogen reagent, which is transformed by the peroxidase label to brown-colored precipitate at site of antigen in the tissue. Diaminobenzidine (DAB) developed by Dako (USA), is the chromogen used.
Positive and Negative Control:
A tissue was processed by phosphate buffer solution instead of the primary antibody, was used as a negative control. Positive external control which represented by sections of squamous cell carcinoma for both markers.
Evaluation of Immunostaining:
For both markers, positive staining was indicated as brown color in the nucleus of the cells, but cytoplasmic staining was also recorded (Zhang et al., 2014). For both markers, Scoring was done by taking into account both the intensity of staining and the extent (ratio of positive cells). The percentage of positive-staining cells were graded on a scale of 0-3, with less than 5% positive-staining cells as (grade 0), ¬ 5-25% as (grade 1), 26-50% as (grade 2), and more than 50% as (grade 3). The intensity of stain¬ing also graded on a scale of 0-2, with negative to weak intensity as (grade 0), weak-moderate inten¬sity as (grade 1), and mod¬erate to strong intensity as (grade 2). For each marker, the score of per¬centage and intensity was multiplied. The final score between 0-2 was determined as low expression, and score higher than 2 was determined as high expression (Zhang et al., 2014).
Statistical analysis
Recorded data were analyzed using the statistical package for social sciences, version 20.0 (SPSS Inc., Chicago, Illinois, USA). Quantitative data were expressed as mean± standard deviation (SD). Qualitative data were expressed as frequency and percentage. The following tests were done: Chi-square (x2) test of significance was used in order to compare proportions between qualitative parameters, Pearson's correlation coefficient (r) test was used to calculate the degree of association between two sets of variables. The confidence interval was set to 95% and the margin of error accepted was set to 5%. So, the P-value was considered significant as the following: P-value < 0.05 was considered significant, P-value < 0.001 was considered as highly significant, while P-value > 0.05 was considered insignificant."