diff --git a/README.md b/README.md
index 3202051..a324ca6 100644
--- a/README.md
+++ b/README.md
@@ -13,6 +13,11 @@
 
 Modified by wym6912 wym6912@outlook.com
 
+## Updates (v1.4.1.2)
+
+- Fix bug in outputting RNA sequences in `v1.4.1.1`
+- Add `BLOSUM62` matrix arugment (`-B/--blosum`)
+
 ## Updates (v1.4.1.1)
 
 - Add Windows compile support in `Visual Studio 2022`
diff --git a/abPOA.rc b/abPOA.rc
index e95f8ac..48b2c8a 100644
Binary files a/abPOA.rc and b/abPOA.rc differ
diff --git a/include/abpoa.h b/include/abpoa.h
index 87bbdcf..e24935a 100644
--- a/include/abpoa.h
+++ b/include/abpoa.h
@@ -75,6 +75,7 @@ typedef struct {
     int align_mode, gap_mode, max_n_cons;
     double min_freq; // for multiploid data
     int verbose; // to control output msg
+    int has_u; // detect RNA sequences
 
     // char LogTable65536[65536];
     // char bit_table16[65536];
diff --git a/src/abpoa.c b/src/abpoa.c
index 93e46b5..8b18ae8 100644
--- a/src/abpoa.c
+++ b/src/abpoa.c
@@ -20,7 +20,7 @@ char PROG[20] = "abpoa";
 #define _bO BOLD UNDERLINE "O" NONE
 #define _bA BOLD UNDERLINE "A" NONE
 char DESCRIPTION[200] = _ba "daptive " _bb "anded " _bP "artial " _bO "rder " _bA "lignment";
-char VERSION[20] = "1.4.1.1";
+char VERSION[20] = "1.4.1.2";
 char CONTACT[30] = "gaoy1@chop.edu";
 
 const struct option abpoa_long_opt [] = {
@@ -55,6 +55,7 @@ const struct option abpoa_long_opt [] = {
     { "out-pog", 1, NULL, 'g' },
     { "max-num-cons", 1, NULL, 'd', },
     { "min-freq", 1, NULL, 'q', },
+    { "blosum", 0, NULL, 'B', },
 
     { "help", 0, NULL, 'h' },
     { "version", 0, NULL, 'v' },
@@ -115,6 +116,7 @@ int abpoa_usage(void)
     err_printf("  Input/Output:\n");
     err_printf("    -Q --use-qual-weight    take base quality score from FASTQ input file as graph edge weight [False]\n");
     err_printf("    -c --amino-acid         input sequences are amino acid (default is nucleotide) [False]\n");
+    err_printf("    -B --blosum             use BLOSUM62 for protein alignment [False]\n");
     err_printf("    -l --in-list            input file is a list of sequence file names [False]\n");
     err_printf("                            each line is one sequence file containing a set of sequences\n");
     err_printf("                            which will be aligned by abPOA to generate a consensus sequence\n");
@@ -161,7 +163,7 @@ int abpoa_main(char *file_fn, int is_list, abpoa_para_t *abpt){
 
 int main(int argc, char **argv) {
     int c, m, in_list=0; char *s; abpoa_para_t *abpt = abpoa_init_para();
-    while ((c = getopt_long(argc, argv, "m:M:X:t:O:E:b:f:z:e:QSk:w:n:i:clpso:r:g:d:q:hvV:", abpoa_long_opt, NULL)) >= 0) {
+    while ((c = getopt_long(argc, argv, "m:M:X:t:O:E:b:f:z:e:QSk:w:n:i:clpsBo:r:g:d:q:hvV:", abpoa_long_opt, NULL)) >= 0) {
         switch(c)
         {
             case 'm': m = atoi(optarg);
@@ -203,6 +205,7 @@ int main(int argc, char **argv) {
                       else err_printf("Error: unknown output result mode: %s.\n", optarg);
                       break;
             case 'g': abpt->out_pog= strdup(optarg); break;
+            case 'B': abpt->use_score_matrix = 2; break;
 
             case 'd': abpt->max_n_cons = atoi(optarg); break; 
             case 'q': abpt->min_freq = atof(optarg); break;
diff --git a/src/abpoa.h b/src/abpoa.h
index 87bbdcf..e24935a 100644
--- a/src/abpoa.h
+++ b/src/abpoa.h
@@ -75,6 +75,7 @@ typedef struct {
     int align_mode, gap_mode, max_n_cons;
     double min_freq; // for multiploid data
     int verbose; // to control output msg
+    int has_u; // detect RNA sequences
 
     // char LogTable65536[65536];
     // char bit_table16[65536];
diff --git a/src/abpoa_align.c b/src/abpoa_align.c
index 6eee392..43b0c44 100644
--- a/src/abpoa_align.c
+++ b/src/abpoa_align.c
@@ -30,6 +30,7 @@ extern char ab_aa26_table[256];
 extern char ab_aa256_table[256];
 extern char ab_char26_table[256];
 extern char ab_char256_table[256];
+extern char ab_blosum62[][100];
 
 void parse_mat_first_line(char *l, int *order) {
     int i, n;
@@ -84,6 +85,40 @@ void abpoa_set_mat_from_file(abpoa_para_t *abpt, char *mat_fn) {
     free(l); free(order); fclose(fp);
 }
 
+void abpoa_set_mat_from_var(abpoa_para_t *abpt, char** matrix, int abpt_sz)
+{
+    char *this_line = matrix[0];
+    int first_line = 1;
+    if(abpt_sz != abpt->m) 
+    {
+        err_func_printf(__func__, "Warning: matrix length %d is different with default setting (%d). Use default matrix", abpt->m, abpt_sz); 
+        return; 
+    }
+    int *order = (int*)_err_malloc(abpt_sz * sizeof(int));
+    for(; strlen(this_line) > 0; ++ this_line)
+    {
+        if(first_line)
+        {
+            first_line = 0;
+            // get string bases
+            parse_mat_first_line(this_line, order);
+        }
+        else 
+        {
+            // get match/mismatch scores
+            parse_mat_score_line(this_line, order, abpt->m, abpt->mat);
+        }
+    }
+    int i; abpt->min_mis = 0, abpt->max_mat = 0;
+    for (i = 0; i < abpt->m * abpt->m; ++i) {
+        if (abpt->mat[i] > abpt->max_mat)
+            abpt->max_mat = abpt->mat[i];
+        if (-abpt->mat[i] > abpt->min_mis) 
+            abpt->min_mis = -abpt->mat[i];
+    }
+    free(order);
+}
+
 void abpoa_set_gap_mode(abpoa_para_t *abpt) {
     if (abpt->gap_open1 == 0) abpt->gap_mode = ABPOA_LINEAR_GAP;
     else if (abpt->gap_open1 > 0 && abpt->gap_open2 == 0) abpt->gap_mode = ABPOA_AFFINE_GAP;
@@ -115,6 +150,7 @@ abpoa_para_t *abpoa_init_para(void) {
     // number of residue types
     abpt->m = 5; // nucleotide
     abpt->mat = (int*)_err_malloc(abpt->m * abpt->m * sizeof(int));
+    abpt->has_u = 0; // DNA sequence
 
     // score matrix
     abpt->use_score_matrix = 0;
@@ -164,7 +200,14 @@ void abpoa_post_set_para(abpoa_para_t *abpt) {
         }
     }
     if (abpt->use_score_matrix == 0) gen_simple_mat(abpt);
-    else abpoa_set_mat_from_file(abpt, abpt->mat_fn);
+    else if(abpt->use_score_matrix == 1) abpoa_set_mat_from_file(abpt, abpt->mat_fn);
+    else if(abpt->use_score_matrix == 2) 
+    {
+        _err_simple_func_printf("Try to use BLOSUM62 matrix");
+        abpoa_set_mat_from_var(abpt, (char**)ab_blosum62, 26);
+        
+    }
+    else err_fatal_core(__func__, "score matrix = %d, which is unsupported.\n", abpt->use_score_matrix);
 }
 
 void abpoa_free_para(abpoa_para_t *abpt) {
@@ -443,7 +486,7 @@ int abpoa_msa1(abpoa_t *ab, abpoa_para_t *abpt, char *read_fn, FILE *out_fp) {
     abpoa_seq_t *abs = ab->abs; int exist_n_seq = abs->n_seq;
 
     // read seq from read_fn
-    FILE* readfp = fopen(read_fn, "r"); kseq_t *ks = kseq_init(fileno(readfp));
+    FILE* readfp = xopen(read_fn, "r"); kseq_t *ks = kseq_init(fileno(readfp));
     int i, j, n_seq = abpoa_read_seq(abs, ks);
 
     // always reset graph before perform POA
@@ -452,21 +495,46 @@ int abpoa_msa1(abpoa_t *ab, abpoa_para_t *abpt, char *read_fn, FILE *out_fp) {
         if (abs->seq[i].l > max_len) max_len = abs->seq[i].l;
     }
 
+    // detect u and t
+    int has_st = 0, has_su = 0;
+
     // set seqs, seq_lens
     extern char ab_char26_table[256];
     uint8_t **seqs = (uint8_t**)_err_malloc(n_seq * sizeof(uint8_t*)); int *seq_lens = (int*)_err_malloc(n_seq * sizeof(int));
     int **weights = (int**)_err_malloc(n_seq * sizeof(int*));
+    char ch;
     for (i = 0; i < n_seq; ++i) {
         seq_lens[i] = abs->seq[exist_n_seq+i].l;
         seqs[i] = (uint8_t*)_err_malloc(sizeof(uint8_t) * seq_lens[i]);
         weights[i] = (int*)_err_malloc(sizeof(int) * seq_lens[i]);
-        for (j = 0; j < seq_lens[i]; ++j) seqs[i][j] = ab_char26_table[(int)abs->seq[exist_n_seq+i].s[j]];
+        for (j = 0; j < seq_lens[i]; ++j) 
+        {
+            ch = abs->seq[exist_n_seq+i].s[j];
+            seqs[i][j] = ab_char26_table[(int)ch];
+            if(ch == 'U' || ch == 'u') ++ has_su;
+            else if(ch == 'T' || ch == 't') ++ has_st;
+        }
         if (abpt->use_qv && abs->qual[exist_n_seq+i].l > 0) {
             for (j = 0; j < seq_lens[i]; ++j) weights[i][j] = (int)abs->qual[exist_n_seq+i].s[j]-32;
         } else {
             for (j = 0; j < seq_lens[i]; ++j) weights[i][j] = 1;
         }
     }
+    if(abpt->m == 5) // nuc
+    {
+        if(has_st && has_su) err_fatal_core(__func__, "DNA sequence has U and T. Please check the sequences, use --amino-acid or -c if sequences are protein.\n");
+        else if(has_su) 
+        {
+            _err_simple_func_printf("detected RNA sequences");
+            abpt->has_u = 1;
+        }
+        else
+        {
+            _err_simple_func_printf("detected DNA sequences");
+            abpt->has_u = 0;
+        }
+    }
+    else _err_simple_func_printf("detected Protein sequences\n");
     if ((abpt->disable_seeding && abpt->progressive_poa==0) || abpt->align_mode != ABPOA_GLOBAL_MODE) {
         abpoa_poa(ab, abpt, seqs, weights, seq_lens, exist_n_seq, n_seq);
     } else {
diff --git a/src/abpoa_output.c b/src/abpoa_output.c
index 0fc4fb9..7ede4a0 100644
--- a/src/abpoa_output.c
+++ b/src/abpoa_output.c
@@ -70,8 +70,7 @@ abpoa_cons_t *abpoa_allocate_rc_msa(abpoa_cons_t *abc, int msa_len, int n_seq, i
 void abpoa_output_rc_msa(abpoa_t *ab, abpoa_para_t *abpt, FILE *out_fp) {
     if (out_fp == NULL) return;
     // print U in RNA
-    short changedU = (ab_char256_table['U'] != 'U'); char rawU = ab_char256_table['U'];
-    if(changedU) ab_char256_table['U'] = 'U';
+    if(abpt->has_u) ab_char256_table[3] = 'U';
     int i, j;
     abpoa_seq_t *abs = ab->abs; abpoa_cons_t *abc = ab->abc;
     if (abc->msa_len <= 0) return;
@@ -101,7 +100,7 @@ void abpoa_output_rc_msa(abpoa_t *ab, abpoa_para_t *abpt, FILE *out_fp) {
             fprintf(out_fp, "\n");
         }
     }
-    ab_char256_table['U'] = rawU; // revert change
+    ab_char256_table[3] = 'T'; // revert change
 }
 
 void abpoa_set_msa_seq(abpoa_node_t node, int rank, uint8_t **msa_base) {
@@ -190,6 +189,8 @@ void abpoa_generate_gfa(abpoa_t *ab, abpoa_para_t *abpt, FILE *out_fp) {
 
     kdq_int_t *q = kdq_init_int();
 
+    if(abpt->has_u) ab_char256_table[3] = 'U';
+
     // Breadth-First-Search
     kdq_push_int(q, ABPOA_SRC_NODE_ID); 
     while ((id = kdq_shift_int(q)) != 0) {
@@ -269,6 +270,7 @@ void abpoa_generate_gfa(abpoa_t *ab, abpoa_para_t *abpt, FILE *out_fp) {
     free(in_degree);
     for (i = 0; i < n_seq; ++i) free(read_paths[i]); 
     free(read_paths); free(read_path_i);
+    ab_char256_table[3] = 'T';
 }
 
 int abpoa_cons_phred_score(int n_cov, int n_seq) {
@@ -498,6 +500,7 @@ void abpoa_multip_heaviest_bundling(abpoa_graph_t *abg, abpoa_para_t *abpt, int
 
 void abpoa_output_fx_consensus(abpoa_t *ab, abpoa_para_t *abpt, FILE *out_fp) {
     if (out_fp == NULL) return;
+    if(abpt->has_u) ab_char256_table[3] = 'U';
     int cons_i, j;
     abpoa_cons_t *abc = ab->abc;
     for (cons_i = 0; cons_i < abc->n_cons; ++cons_i) {
@@ -529,6 +532,7 @@ void abpoa_output_fx_consensus(abpoa_t *ab, abpoa_para_t *abpt, FILE *out_fp) {
             } fprintf(out_fp, "\n");
         }
     }
+    ab_char256_table[3] = 'T';
 }
 
 abpoa_cons_t *abpoa_allocate_cons(abpoa_cons_t *abc, int n_node, int n_seq, int n_cons) {
diff --git a/src/abpoa_seq.c b/src/abpoa_seq.c
index 3f1bdc1..997e82b 100644
--- a/src/abpoa_seq.c
+++ b/src/abpoa_seq.c
@@ -97,6 +97,38 @@ const char ab_aa256_table[256] = {
 char ab_char26_table[256];
 char ab_char256_table[256];
 
+char ab_blosum62[][100] = {
+    {"A  R  N  D  C  Q  E  G  H  I  L  K  M  F  P  S  T  W  Y  V  B  J  Z  X  *  O  U"},
+    {"A  4 -1 -2 -2  0 -1 -1  0 -2 -1 -1 -1 -1 -2 -1  1  0 -3 -2  0 -2 -1 -1 -1 -4 -4 -4"},
+    {"R -1  5  0 -2 -3  1  0 -2  0 -3 -2  2 -1 -3 -2 -1 -1 -3 -2 -3 -1 -2  0 -1 -4 -4 -4"},
+    {"N -2  0  6  1 -3  0  0  0  1 -3 -3  0 -2 -3 -2  1  0 -4 -2 -3  4 -3  0 -1 -4 -4 -4"},
+    {"D -2 -2  1  6 -3  0  2 -1 -1 -3 -4 -1 -3 -3 -1  0 -1 -4 -3 -3  4 -3  1 -1 -4 -4 -4"},
+    {"C  0 -3 -3 -3  9 -3 -4 -3 -3 -1 -1 -3 -1 -2 -3 -1 -1 -2 -2 -1 -3 -1 -3 -1 -4 -4 -4"},
+    {"Q -1  1  0  0 -3  5  2 -2  0 -3 -2  1  0 -3 -1  0 -1 -2 -1 -2  0 -2  4 -1 -4 -4 -4"},
+    {"E -1  0  0  2 -4  2  5 -2  0 -3 -3  1 -2 -3 -1  0 -1 -3 -2 -2  1 -3  4 -1 -4 -4 -4"},
+    {"G  0 -2  0 -1 -3 -2 -2  6 -2 -4 -4 -2 -3 -3 -2  0 -2 -2 -3 -3 -1 -4 -2 -1 -4 -4 -4"},
+    {"H -2  0  1 -1 -3  0  0 -2  8 -3 -3 -1 -2 -1 -2 -1 -2 -2  2 -3  0 -3  0 -1 -4 -4 -4"},
+    {"I -1 -3 -3 -3 -1 -3 -3 -4 -3  4  2 -3  1  0 -3 -2 -1 -3 -1  3 -3  3 -3 -1 -4 -4 -4"},
+    {"L -1 -2 -3 -4 -1 -2 -3 -4 -3  2  4 -2  2  0 -3 -2 -1 -2 -1  1 -4  3 -3 -1 -4 -4 -4"},
+    {"K -1  2  0 -1 -3  1  1 -2 -1 -3 -2  5 -1 -3 -1  0 -1 -3 -2 -2  0 -3  1 -1 -4 -4 -4"},
+    {"M -1 -1 -2 -3 -1  0 -2 -3 -2  1  2 -1  5  0 -2 -1 -1 -1 -1  1 -3  2 -1 -1 -4 -4 -4"},
+    {"F -2 -3 -3 -3 -2 -3 -3 -3 -1  0  0 -3  0  6 -4 -2 -2  1  3 -1 -3  0 -3 -1 -4 -4 -4"},
+    {"P -1 -2 -2 -1 -3 -1 -1 -2 -2 -3 -3 -1 -2 -4  7 -1 -1 -4 -3 -2 -2 -3 -1 -1 -4 -4 -4"},
+    {"S  1 -1  1  0 -1  0  0  0 -1 -2 -2  0 -1 -2 -1  4  1 -3 -2 -2  0 -2  0 -1 -4 -4 -4"},
+    {"T  0 -1  0 -1 -1 -1 -1 -2 -2 -1 -1 -1 -1 -2 -1  1  5 -2 -2  0 -1 -1 -1 -1 -4 -4 -4"},
+    {"W -3 -3 -4 -4 -2 -2 -3 -2 -2 -3 -2 -3 -1  1 -4 -3 -2 11  2 -3 -4 -2 -2 -1 -4 -4 -4"},
+    {"Y -2 -2 -2 -3 -2 -1 -2 -3  2 -1 -1 -2 -1  3 -3 -2 -2  2  7 -1 -3 -1 -2 -1 -4 -4 -4"},
+    {"V  0 -3 -3 -3 -1 -2 -2 -3 -3  3  1 -2  1 -1 -2 -2  0 -3 -1  4 -3  2 -2 -1 -4 -4 -4"},
+    {"B -2 -1  4  4 -3  0  1 -1  0 -3 -4  0 -3 -3 -2  0 -1 -4 -3 -3  4 -3  0 -1 -4 -4 -4"},
+    {"J -1 -2 -3 -3 -1 -2 -3 -4 -3  3  3 -3  2  0 -3 -2 -1 -2 -1  2 -3  3 -3 -1 -4 -4 -4"},
+    {"Z -1  0  0  1 -3  4  4 -2  0 -3 -3  1 -1 -3 -1  0 -1 -2 -2 -2  0 -3  4 -1 -4 -4 -4"},
+    {"X -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -4 -4 -4"},
+    {"* -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4  1 -4 -4"},
+    {"O -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4  1 -4"},
+    {"U -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4 -4  1"},
+    {""}
+};
+
 abpoa_seq_t *abpoa_init_seq(void) {
     abpoa_seq_t *abs = (abpoa_seq_t*)_err_malloc(sizeof(abpoa_seq_t));
     abs->n_seq = 0; abs->m_seq = CHUNK_READ_N;